Add 'nixpkgs/' from commit 'abf060725d7614bd3b9f96764262dfbc2f9c2199'

git-subtree-dir: nixpkgs
git-subtree-mainline: 4e31070265257dc67d120c27e0f75c2344fdfa9a
git-subtree-split: abf060725d7614bd3b9f96764262dfbc2f9c2199

57 files changed, 18496 insertions, 0 deletions

diff --git a/nixpkgs/doc/.gitignore b/nixpkgs/doc/.gitignore
new file mode 100644
index 000000000000..cb07135e6858
--- /dev/null
+++ b/nixpkgs/doc/.gitignore
@@ -0,0 +1,7 @@
+*.chapter.xml
+*.section.xml
+.version
+out
+manual-full.xml
+highlightjs
+functions/library/locations.xml
diff --git a/nixpkgs/doc/Makefile b/nixpkgs/doc/Makefile
new file mode 100644
index 000000000000..c6aed62a9396
--- /dev/null
+++ b/nixpkgs/doc/Makefile
@@ -0,0 +1,104 @@
+MD_TARGETS=$(addsuffix .xml, $(basename $(wildcard ./*.md ./**/*.md)))
+
+.PHONY: all
+all: validate format out/html/index.html out/epub/manual.epub
+
+.PHONY: debug
+debug:
+	nix-shell --run "xmloscopy --docbook5 ./manual.xml ./manual-full.xml"
+
+.PHONY: format
+format:
+	find . -iname '*.xml' -type f -print0 | xargs -0 -I{} -n1 \
+		xmlformat --config-file "$$XMLFORMAT_CONFIG" -i {}
+
+.PHONY: fix-misc-xml
+fix-misc-xml:
+	find . -iname '*.xml' -type f \
+		-exec ../nixos/doc/varlistentry-fixer.rb {} ';'
+
+.PHONY: clean
+clean:
+	rm -f ${MD_TARGETS} .version manual-full.xml functions/library/locations.xml
+	rm -rf ./out/ ./highlightjs
+
+.PHONY: validate
+validate: manual-full.xml
+	jing "$$RNG" manual-full.xml
+
+out/html/index.html: manual-full.xml style.css highlightjs
+	mkdir -p out/html
+	xsltproc ${xsltFlags} \
+		--nonet --xinclude \
+		--output $@ \
+		"$$XSL/docbook/xhtml/docbook.xsl" \
+		./manual-full.xml
+
+	mkdir -p out/html/highlightjs/
+	cp -r highlightjs out/html/
+
+	cp ./overrides.css out/html/
+	cp ./style.css out/html/style.css
+
+	mkdir -p out/html/images/callouts
+	cp "$$XSL/docbook/images/callouts/"*.svg out/html/images/callouts/
+	chmod u+w -R out/html/
+
+out/epub/manual.epub: manual-full.xml
+	mkdir -p out/epub/scratch
+	xsltproc ${xsltFlags} --nonet \
+		--output out/epub/scratch/ \
+		"$$XSL/docbook/epub/docbook.xsl" \
+		./manual-full.xml
+
+	cp ./overrides.css out/epub/scratch/OEBPS
+	cp ./style.css out/epub/scratch/OEBPS
+	mkdir -p out/epub/scratch/OEBPS/images/callouts/
+	cp "$$XSL/docbook/images/callouts/"*.svg out/epub/scratch/OEBPS/images/callouts/
+	echo "application/epub+zip" > mimetype
+	zip -0Xq "out/epub/manual.epub" mimetype
+	rm mimetype
+	cd "out/epub/scratch/" && zip -Xr9D "../manual.epub" *
+	rm -rf "out/epub/scratch/"
+
+highlightjs:
+	mkdir -p highlightjs
+	cp -r "$$HIGHLIGHTJS/highlight.pack.js" highlightjs/
+	cp -r "$$HIGHLIGHTJS/LICENSE" highlightjs/
+	cp -r "$$HIGHLIGHTJS/mono-blue.css" highlightjs/
+	cp -r "$$HIGHLIGHTJS/loader.js" highlightjs/
+
+
+manual-full.xml: ${MD_TARGETS} .version functions/library/locations.xml *.xml **/*.xml **/**/*.xml
+	xmllint --nonet --xinclude --noxincludenode manual.xml --output manual-full.xml
+
+.version:
+	nix-instantiate --eval \
+		-E '(import ../lib).version' > .version
+
+functions/library/locations.xml:
+	nix-build ./lib-function-locations.nix \
+		--out-link ./functions/library/locations.xml
+
+%.section.xml: %.section.md
+	pandoc $^ -w docbook+smart \
+		-f markdown+smart \
+	  | sed -e 's|<ulink url=|<link xlink:href=|' \
+	      -e 's|</ulink>|</link>|' \
+	      -e 's|<sect. id=|<section xml:id=|' \
+	      -e 's|</sect[0-9]>|</section>|' \
+	      -e '1s| id=| xml:id=|' \
+	      -e '1s|\(<[^ ]* \)|\1xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" |' \
+	| cat  > $@
+
+%.chapter.xml: %.chapter.md
+	pandoc $^ -w docbook+smart \
+		--top-level-division=chapter \
+		-f markdown+smart \
+	  | sed -e 's|<ulink url=|<link xlink:href=|' \
+	      -e 's|</ulink>|</link>|' \
+	      -e 's|<sect. id=|<section xml:id=|' \
+	      -e 's|</sect[0-9]>|</section>|' \
+	      -e '1s| id=| xml:id=|' \
+	      -e '1s|\(<[^ ]* \)|\1|' \
+	| cat  > $@
diff --git a/nixpkgs/doc/coding-conventions.xml b/nixpkgs/doc/coding-conventions.xml
new file mode 100644
index 000000000000..a8a4557b461c
--- /dev/null
+++ b/nixpkgs/doc/coding-conventions.xml
@@ -0,0 +1,948 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-conventions">
+ <title>Coding conventions</title>
+ <section xml:id="sec-syntax">
+  <title>Syntax</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Use 2 spaces of indentation per indentation level in Nix expressions, 4
+     spaces in shell scripts.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Do not use tab characters, i.e. configure your editor to use soft tabs.
+     For instance, use <literal>(setq-default indent-tabs-mode nil)</literal>
+     in Emacs. Everybody has different tab settings so it’s asking for
+     trouble.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Use <literal>lowerCamelCase</literal> for variable names, not
+     <literal>UpperCamelCase</literal>. Note, this rule does not apply to
+     package attribute names, which instead follow the rules in
+     <xref linkend="sec-package-naming"/>.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Function calls with attribute set arguments are written as
+<programlisting>
+foo {
+  arg = ...;
+}
+</programlisting>
+     not
+<programlisting>
+foo
+{
+  arg = ...;
+}
+</programlisting>
+     Also fine is
+<programlisting>
+foo { arg = ...; }
+</programlisting>
+     if it's a short call.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     In attribute sets or lists that span multiple lines, the attribute names
+     or list elements should be aligned:
+<programlisting>
+# A long list.
+list = [
+  elem1
+  elem2
+  elem3
+];
+
+# A long attribute set.
+attrs = {
+  attr1 = short_expr;
+  attr2 =
+    if true then big_expr else big_expr;
+};
+
+# Combined
+listOfAttrs = [
+  {
+    attr1 = 3;
+    attr2 = "fff";
+  }
+  {
+    attr1 = 5;
+    attr2 = "ggg";
+  }
+];
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Short lists or attribute sets can be written on one line:
+<programlisting>
+# A short list.
+list = [ elem1 elem2 elem3 ];
+
+# A short set.
+attrs = { x = 1280; y = 1024; };
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Breaking in the middle of a function argument can give hard-to-read code,
+     like
+<programlisting>
+someFunction { x = 1280;
+  y = 1024; } otherArg
+  yetAnotherArg
+</programlisting>
+     (especially if the argument is very large, spanning multiple lines).
+    </para>
+    <para>
+     Better:
+<programlisting>
+someFunction
+  { x = 1280; y = 1024; }
+  otherArg
+  yetAnotherArg
+</programlisting>
+     or
+<programlisting>
+let res = { x = 1280; y = 1024; };
+in someFunction res otherArg yetAnotherArg
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     The bodies of functions, asserts, and withs are not indented to prevent a
+     lot of superfluous indentation levels, i.e.
+<programlisting>
+{ arg1, arg2 }:
+assert system == "i686-linux";
+stdenv.mkDerivation { ...
+</programlisting>
+     not
+<programlisting>
+{ arg1, arg2 }:
+  assert system == "i686-linux";
+    stdenv.mkDerivation { ...
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Function formal arguments are written as:
+<programlisting>
+{ arg1, arg2, arg3 }:
+</programlisting>
+     but if they don't fit on one line they're written as:
+<programlisting>
+{ arg1, arg2, arg3
+, arg4, ...
+, # Some comment...
+  argN
+}:
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Functions should list their expected arguments as precisely as possible.
+     That is, write
+<programlisting>
+{ stdenv, fetchurl, perl }: <replaceable>...</replaceable>
+</programlisting>
+     instead of
+<programlisting>
+args: with args; <replaceable>...</replaceable>
+</programlisting>
+     or
+<programlisting>
+{ stdenv, fetchurl, perl, ... }: <replaceable>...</replaceable>
+</programlisting>
+    </para>
+    <para>
+     For functions that are truly generic in the number of arguments (such as
+     wrappers around <varname>mkDerivation</varname>) that have some required
+     arguments, you should write them using an <literal>@</literal>-pattern:
+<programlisting>
+{ stdenv, doCoverageAnalysis ? false, ... } @ args:
+
+stdenv.mkDerivation (args // {
+  <replaceable>...</replaceable> if doCoverageAnalysis then "bla" else "" <replaceable>...</replaceable>
+})
+</programlisting>
+     instead of
+<programlisting>
+args:
+
+args.stdenv.mkDerivation (args // {
+  <replaceable>...</replaceable> if args ? doCoverageAnalysis &amp;&amp; args.doCoverageAnalysis then "bla" else "" <replaceable>...</replaceable>
+})
+</programlisting>
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+ <section xml:id="sec-package-naming">
+  <title>Package naming</title>
+
+  <para>
+    The key words
+    <emphasis>must</emphasis>,
+    <emphasis>must not</emphasis>,
+    <emphasis>required</emphasis>,
+    <emphasis>shall</emphasis>,
+    <emphasis>shall not</emphasis>,
+    <emphasis>should</emphasis>,
+    <emphasis>should not</emphasis>,
+    <emphasis>recommended</emphasis>,
+    <emphasis>may</emphasis>,
+    and <emphasis>optional</emphasis> in this section
+    are to be interpreted as described in
+    <link xlink:href="https://tools.ietf.org/html/rfc2119">RFC 2119</link>.
+    Only <emphasis>emphasized</emphasis> words are to be interpreted in this way.
+  </para>
+
+  <para>
+   In Nixpkgs, there are generally three different names associated with a
+   package:
+   <itemizedlist>
+    <listitem>
+     <para>
+      The <varname>name</varname> attribute of the derivation (excluding the
+      version part). This is what most users see, in particular when using
+      <command>nix-env</command>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The variable name used for the instantiated package in
+      <filename>all-packages.nix</filename>, and when passing it as a
+      dependency to other functions. Typically this is called the
+      <emphasis>package attribute name</emphasis>. This is what Nix expression
+      authors see. It can also be used when installing using <command>nix-env
+      -iA</command>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The filename for (the directory containing) the Nix expression.
+     </para>
+    </listitem>
+   </itemizedlist>
+   Most of the time, these are the same. For instance, the package
+   <literal>e2fsprogs</literal> has a <varname>name</varname> attribute
+   <literal>"e2fsprogs-<replaceable>version</replaceable>"</literal>, is bound
+   to the variable name <varname>e2fsprogs</varname> in
+   <filename>all-packages.nix</filename>, and the Nix expression is in
+   <filename>pkgs/os-specific/linux/e2fsprogs/default.nix</filename>.
+  </para>
+
+  <para>
+   There are a few naming guidelines:
+   <itemizedlist>
+    <listitem>
+     <para>
+       The <literal>name</literal> attribute <emphasis>should</emphasis>
+       be identical to the upstream package name.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       The <literal>name</literal> attribute <emphasis>must not</emphasis>
+       contain uppercase letters — e.g., <literal>"mplayer-1.0rc2"</literal>
+       instead of <literal>"MPlayer-1.0rc2"</literal>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The version part of the <literal>name</literal> attribute
+      <emphasis>must</emphasis> start with a digit (following a dash) — e.g.,
+      <literal>"hello-0.3.1rc2"</literal>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      If a package is not a release but a commit from a repository, then the
+      version part of the name <emphasis>must</emphasis> be the date of that
+      (fetched) commit. The date <emphasis>must</emphasis> be in <literal>"YYYY-MM-DD"</literal>
+      format. Also append <literal>"unstable"</literal> to the name - e.g.,
+      <literal>"pkgname-unstable-2014-09-23"</literal>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Dashes in the package name <emphasis>should</emphasis> be preserved in new variable names,
+      rather than converted to underscores or camel cased — e.g.,
+      <varname>http-parser</varname> instead of <varname>http_parser</varname>
+      or <varname>httpParser</varname>. The hyphenated style is preferred in
+      all three package names.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      If there are multiple versions of a package, this <emphasis>should</emphasis> be reflected in
+      the variable names in <filename>all-packages.nix</filename>, e.g.
+      <varname>json-c-0-9</varname> and <varname>json-c-0-11</varname>. If
+      there is an obvious “default” version, make an attribute like
+      <literal>json-c = json-c-0-9;</literal>. See also
+      <xref linkend="sec-versioning" />
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+ </section>
+ <section xml:id="sec-organisation">
+  <title>File naming and organisation</title>
+
+  <para>
+   Names of files and directories should be in lowercase, with dashes between
+   words — not in camel case. For instance, it should be
+   <filename>all-packages.nix</filename>, not
+   <filename>allPackages.nix</filename> or
+   <filename>AllPackages.nix</filename>.
+  </para>
+
+  <section xml:id="sec-hierarchy">
+   <title>Hierarchy</title>
+
+   <para>
+    Each package should be stored in its own directory somewhere in the
+    <filename>pkgs/</filename> tree, i.e. in
+    <filename>pkgs/<replaceable>category</replaceable>/<replaceable>subcategory</replaceable>/<replaceable>...</replaceable>/<replaceable>pkgname</replaceable></filename>.
+    Below are some rules for picking the right category for a package. Many
+    packages fall under several categories; what matters is the
+    <emphasis>primary</emphasis> purpose of a package. For example, the
+    <literal>libxml2</literal> package builds both a library and some tools;
+    but it’s a library foremost, so it goes under
+    <filename>pkgs/development/libraries</filename>.
+   </para>
+
+   <para>
+    When in doubt, consider refactoring the <filename>pkgs/</filename> tree,
+    e.g. creating new categories or splitting up an existing category.
+   </para>
+
+   <variablelist>
+    <varlistentry>
+     <term>
+      If it’s used to support <emphasis>software development</emphasis>:
+     </term>
+     <listitem>
+      <variablelist>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>library</emphasis> used by other packages:
+        </term>
+        <listitem>
+         <para>
+          <filename>development/libraries</filename> (e.g.
+          <filename>libxml2</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>compiler</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>development/compilers</filename> (e.g.
+          <filename>gcc</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s an <emphasis>interpreter</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>development/interpreters</filename> (e.g.
+          <filename>guile</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a (set of) development <emphasis>tool(s)</emphasis>:
+        </term>
+        <listitem>
+         <variablelist>
+          <varlistentry>
+           <term>
+            If it’s a <emphasis>parser generator</emphasis> (including lexers):
+           </term>
+           <listitem>
+            <para>
+             <filename>development/tools/parsing</filename> (e.g.
+             <filename>bison</filename>, <filename>flex</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            If it’s a <emphasis>build manager</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             <filename>development/tools/build-managers</filename> (e.g.
+             <filename>gnumake</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            Else:
+           </term>
+           <listitem>
+            <para>
+             <filename>development/tools/misc</filename> (e.g.
+             <filename>binutils</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+         </variablelist>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         Else:
+        </term>
+        <listitem>
+         <para>
+          <filename>development/misc</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a (set of) <emphasis>tool(s)</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       (A tool is a relatively small program, especially one intended to be
+       used non-interactively.)
+      </para>
+      <variablelist>
+       <varlistentry>
+        <term>
+         If it’s for <emphasis>networking</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/networking</filename> (e.g.
+          <filename>wget</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s for <emphasis>text processing</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/text</filename> (e.g. <filename>diffutils</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>system utility</emphasis>, i.e., something related or essential to the operation of a system:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/system</filename> (e.g. <filename>cron</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s an <emphasis>archiver</emphasis> (which may include a compression function):
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/archivers</filename> (e.g. <filename>zip</filename>,
+          <filename>tar</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>compression</emphasis> program:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/compression</filename> (e.g.
+          <filename>gzip</filename>, <filename>bzip2</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>security</emphasis>-related program:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/security</filename> (e.g. <filename>nmap</filename>,
+          <filename>gnupg</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         Else:
+        </term>
+        <listitem>
+         <para>
+          <filename>tools/misc</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a <emphasis>shell</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       <filename>shells</filename> (e.g. <filename>bash</filename>)
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a <emphasis>server</emphasis>:
+     </term>
+     <listitem>
+      <variablelist>
+       <varlistentry>
+        <term>
+         If it’s a web server:
+        </term>
+        <listitem>
+         <para>
+          <filename>servers/http</filename> (e.g.
+          <filename>apache-httpd</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s an implementation of the X Windowing System:
+        </term>
+        <listitem>
+         <para>
+          <filename>servers/x11</filename> (e.g. <filename>xorg</filename> —
+          this includes the client libraries and programs)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         Else:
+        </term>
+        <listitem>
+         <para>
+          <filename>servers/misc</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a <emphasis>desktop environment</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       <filename>desktops</filename> (e.g. <filename>kde</filename>,
+       <filename>gnome</filename>, <filename>enlightenment</filename>)
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a <emphasis>window manager</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       <filename>applications/window-managers</filename> (e.g.
+       <filename>awesome</filename>, <filename>stumpwm</filename>)
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s an <emphasis>application</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       A (typically large) program with a distinct user interface, primarily
+       used interactively.
+      </para>
+      <variablelist>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>version management system</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>applications/version-management</filename> (e.g.
+          <filename>subversion</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s for <emphasis>video playback / editing</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>applications/video</filename> (e.g.
+          <filename>vlc</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s for <emphasis>graphics viewing / editing</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>applications/graphics</filename> (e.g.
+          <filename>gimp</filename>)
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s for <emphasis>networking</emphasis>:
+        </term>
+        <listitem>
+         <variablelist>
+          <varlistentry>
+           <term>
+            If it’s a <emphasis>mailreader</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             <filename>applications/networking/mailreaders</filename> (e.g.
+             <filename>thunderbird</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            If it’s a <emphasis>newsreader</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             <filename>applications/networking/newsreaders</filename> (e.g.
+             <filename>pan</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            If it’s a <emphasis>web browser</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             <filename>applications/networking/browsers</filename> (e.g.
+             <filename>firefox</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            Else:
+           </term>
+           <listitem>
+            <para>
+             <filename>applications/networking/misc</filename>
+            </para>
+           </listitem>
+          </varlistentry>
+         </variablelist>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         Else:
+        </term>
+        <listitem>
+         <para>
+          <filename>applications/misc</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s <emphasis>data</emphasis> (i.e., does not have a straight-forward executable semantics):
+     </term>
+     <listitem>
+      <variablelist>
+       <varlistentry>
+        <term>
+         If it’s a <emphasis>font</emphasis>:
+        </term>
+        <listitem>
+         <para>
+          <filename>data/fonts</filename>
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         If it’s related to <emphasis>SGML/XML processing</emphasis>:
+        </term>
+        <listitem>
+         <variablelist>
+          <varlistentry>
+           <term>
+            If it’s an <emphasis>XML DTD</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             <filename>data/sgml+xml/schemas/xml-dtd</filename> (e.g.
+             <filename>docbook</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+          <varlistentry>
+           <term>
+            If it’s an <emphasis>XSLT stylesheet</emphasis>:
+           </term>
+           <listitem>
+            <para>
+             (Okay, these are executable...)
+            </para>
+            <para>
+             <filename>data/sgml+xml/stylesheets/xslt</filename> (e.g.
+             <filename>docbook-xsl</filename>)
+            </para>
+           </listitem>
+          </varlistentry>
+         </variablelist>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      If it’s a <emphasis>game</emphasis>:
+     </term>
+     <listitem>
+      <para>
+       <filename>games</filename>
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      Else:
+     </term>
+     <listitem>
+      <para>
+       <filename>misc</filename>
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="sec-versioning">
+   <title>Versioning</title>
+
+   <para>
+    Because every version of a package in Nixpkgs creates a potential
+    maintenance burden, old versions of a package should not be kept unless
+    there is a good reason to do so. For instance, Nixpkgs contains several
+    versions of GCC because other packages don’t build with the latest
+    version of GCC. Other examples are having both the latest stable and latest
+    pre-release version of a package, or to keep several major releases of an
+    application that differ significantly in functionality.
+   </para>
+
+   <para>
+    If there is only one version of a package, its Nix expression should be
+    named <filename>e2fsprogs/default.nix</filename>. If there are multiple
+    versions, this should be reflected in the filename, e.g.
+    <filename>e2fsprogs/1.41.8.nix</filename> and
+    <filename>e2fsprogs/1.41.9.nix</filename>. The version in the filename
+    should leave out unnecessary detail. For instance, if we keep the latest
+    Firefox 2.0.x and 3.5.x versions in Nixpkgs, they should be named
+    <filename>firefox/2.0.nix</filename> and
+    <filename>firefox/3.5.nix</filename>, respectively (which, at a given
+    point, might contain versions <literal>2.0.0.20</literal> and
+    <literal>3.5.4</literal>). If a version requires many auxiliary files, you
+    can use a subdirectory for each version, e.g.
+    <filename>firefox/2.0/default.nix</filename> and
+    <filename>firefox/3.5/default.nix</filename>.
+   </para>
+
+   <para>
+    All versions of a package <emphasis>must</emphasis> be included in
+    <filename>all-packages.nix</filename> to make sure that they evaluate
+    correctly.
+   </para>
+  </section>
+ </section>
+ <section xml:id="sec-sources">
+  <title>Fetching Sources</title>
+
+  <para>
+   There are multiple ways to fetch a package source in nixpkgs. The general
+   guideline is that you should package sources with a high degree of
+   availability. Right now there is only one fetcher which has mirroring
+   support and that is <literal>fetchurl</literal>. Note that you should also
+   prefer protocols which have a corresponding proxy environment variable.
+  </para>
+
+  <para>
+   You can find many source fetch helpers in
+   <literal>pkgs/build-support/fetch*</literal>.
+  </para>
+
+  <para>
+   In the file <literal>pkgs/top-level/all-packages.nix</literal> you can find
+   fetch helpers, these have names on the form <literal>fetchFrom*</literal>.
+   The intention of these are to provide snapshot fetches but using the same
+   api as some of the version controlled fetchers from
+   <literal>pkgs/build-support/</literal>. As an example going from bad to
+   good:
+   <itemizedlist>
+    <listitem>
+     <para>
+      Bad: Uses <literal>git://</literal> which won't be proxied.
+<programlisting>
+src = fetchgit {
+  url = "git://github.com/NixOS/nix.git";
+  rev = "1f795f9f44607cc5bec70d1300150bfefcef2aae";
+  sha256 = "1cw5fszffl5pkpa6s6wjnkiv6lm5k618s32sp60kvmvpy7a2v9kg";
+}
+</programlisting>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Better: This is ok, but an archive fetch will still be faster.
+<programlisting>
+src = fetchgit {
+  url = "https://github.com/NixOS/nix.git";
+  rev = "1f795f9f44607cc5bec70d1300150bfefcef2aae";
+  sha256 = "1cw5fszffl5pkpa6s6wjnkiv6lm5k618s32sp60kvmvpy7a2v9kg";
+}
+</programlisting>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Best: Fetches a snapshot archive and you get the rev you want.
+<programlisting>
+src = fetchFromGitHub {
+  owner = "NixOS";
+  repo = "nix";
+  rev = "1f795f9f44607cc5bec70d1300150bfefcef2aae";
+  sha256 = "1i2yxndxb6yc9l6c99pypbd92lfq5aac4klq7y2v93c9qvx2cgpc";
+}
+</programlisting>
+      Find the value to put as <literal>sha256</literal> by running
+      <literal>nix run -f '&lt;nixpkgs&gt;' nix-prefetch-github -c nix-prefetch-github --rev 1f795f9f44607cc5bec70d1300150bfefcef2aae NixOS nix</literal>
+      or <literal>nix-prefetch-url --unpack https://github.com/NixOS/nix/archive/1f795f9f44607cc5bec70d1300150bfefcef2aae.tar.gz</literal>.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+ </section>
+ <section xml:id="sec-patches">
+  <title>Patches</title>
+
+  <para>
+   Patches available online should be retrieved using
+   <literal>fetchpatch</literal>.
+  </para>
+
+  <para>
+<programlisting>
+patches = [
+  (fetchpatch {
+    name = "fix-check-for-using-shared-freetype-lib.patch";
+    url = "http://git.ghostscript.com/?p=ghostpdl.git;a=patch;h=8f5d285";
+    sha256 = "1f0k043rng7f0rfl9hhb89qzvvksqmkrikmm38p61yfx51l325xr";
+  })
+];
+</programlisting>
+  </para>
+
+  <para>
+   Otherwise, you can add a <literal>.patch</literal> file to the
+   <literal>nixpkgs</literal> repository. In the interest of keeping our
+   maintenance burden to a minimum, only patches that are unique to
+   <literal>nixpkgs</literal> should be added in this way.
+  </para>
+
+  <para>
+<programlisting>
+patches = [ ./0001-changes.patch ];
+</programlisting>
+  </para>
+
+  <para>
+   If you do need to do create this sort of patch file, one way to do so is
+   with git:
+   <orderedlist>
+    <listitem>
+     <para>
+      Move to the root directory of the source code you're patching.
+<screen>
+$ cd the/program/source</screen>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      If a git repository is not already present, create one and stage all of
+      the source files.
+<screen>
+$ git init
+$ git add .</screen>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Edit some files to make whatever changes need to be included in the
+      patch.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Use git to create a diff, and pipe the output to a patch file:
+<screen>
+$ git diff > nixpkgs/pkgs/the/package/0001-changes.patch</screen>
+     </para>
+    </listitem>
+   </orderedlist>
+  </para>
+ </section>
+</chapter>
diff --git a/nixpkgs/doc/configuration.xml b/nixpkgs/doc/configuration.xml
new file mode 100644
index 000000000000..624a5bb270ab
--- /dev/null
+++ b/nixpkgs/doc/configuration.xml
@@ -0,0 +1,510 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-packageconfig">
+ <title>Global configuration</title>
+ <para>
+  Nix comes with certain defaults about what packages can and cannot be
+  installed, based on a package's metadata. By default, Nix will prevent
+  installation if any of the following criteria are true:
+ </para>
+ <itemizedlist>
+  <listitem>
+   <para>
+    The package is thought to be broken, and has had its
+    <literal>meta.broken</literal> set to <literal>true</literal>.
+   </para>
+  </listitem>
+  <listitem>
+   <para>
+    The package isn't intended to run on the given system, as none of its
+    <literal>meta.platforms</literal> match the given system.
+   </para>
+  </listitem>
+  <listitem>
+   <para>
+    The package's <literal>meta.license</literal> is set to a license which is
+    considered to be unfree.
+   </para>
+  </listitem>
+  <listitem>
+   <para>
+    The package has known security vulnerabilities but has not or can not be
+    updated for some reason, and a list of issues has been entered in to the
+    package's <literal>meta.knownVulnerabilities</literal>.
+   </para>
+  </listitem>
+ </itemizedlist>
+ <para>
+  Note that all this is checked during evaluation already, and the check
+  includes any package that is evaluated. In particular, all build-time
+  dependencies are checked. <literal>nix-env -qa</literal> will (attempt to)
+  hide any packages that would be refused.
+ </para>
+ <para>
+  Each of these criteria can be altered in the nixpkgs configuration.
+ </para>
+ <para>
+  The nixpkgs configuration for a NixOS system is set in the
+  <literal>configuration.nix</literal>, as in the following example:
+<programlisting>
+{
+  nixpkgs.config = {
+    allowUnfree = true;
+  };
+}
+</programlisting>
+  However, this does not allow unfree software for individual users. Their
+  configurations are managed separately.
+ </para>
+ <para>
+  A user's of nixpkgs configuration is stored in a user-specific configuration
+  file located at <filename>~/.config/nixpkgs/config.nix</filename>. For
+  example:
+<programlisting>
+{
+  allowUnfree = true;
+}
+</programlisting>
+ </para>
+ <para>
+  Note that we are not able to test or build unfree software on Hydra due to
+  policy. Most unfree licenses prohibit us from either executing or
+  distributing the software.
+ </para>
+ <section xml:id="sec-allow-broken">
+  <title>Installing broken packages</title>
+
+  <para>
+   There are two ways to try compiling a package which has been marked as
+   broken.
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     For allowing the build of a broken package once, you can use an
+     environment variable for a single invocation of the nix tools:
+<programlisting>$ export NIXPKGS_ALLOW_BROKEN=1</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     For permanently allowing broken packages to be built, you may add
+     <literal>allowBroken = true;</literal> to your user's configuration file,
+     like this:
+<programlisting>
+{
+  allowBroken = true;
+}
+</programlisting>
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+ <section xml:id="sec-allow-unsupported-system">
+  <title>Installing packages on unsupported systems</title>
+
+  <para>
+   There are also two ways to try compiling a package which has been marked as
+   unsuported for the given system.
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     For allowing the build of a broken package once, you can use an
+     environment variable for a single invocation of the nix tools:
+<programlisting>$ export NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     For permanently allowing broken packages to be built, you may add
+     <literal>allowUnsupportedSystem = true;</literal> to your user's
+     configuration file, like this:
+<programlisting>
+{
+  allowUnsupportedSystem = true;
+}
+</programlisting>
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <para>
+   The difference between a package being unsupported on some system and
+   being broken is admittedly a bit fuzzy. If a program
+   <emphasis>ought</emphasis> to work on a certain platform, but doesn't, the
+   platform should be included in <literal>meta.platforms</literal>, but marked
+   as broken with e.g. <literal>meta.broken =
+   !hostPlatform.isWindows</literal>. Of course, this begs the question of what
+   "ought" means exactly. That is left to the package maintainer.
+  </para>
+ </section>
+ <section xml:id="sec-allow-unfree">
+  <title>Installing unfree packages</title>
+
+  <para>
+   There are several ways to tweak how Nix handles a package which has been
+   marked as unfree.
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     To temporarily allow all unfree packages, you can use an environment
+     variable for a single invocation of the nix tools:
+<programlisting>$ export NIXPKGS_ALLOW_UNFREE=1</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     It is possible to permanently allow individual unfree packages, while
+     still blocking unfree packages by default using the
+     <literal>allowUnfreePredicate</literal> configuration option in the user
+     configuration file.
+    </para>
+    <para>
+     This option is a function which accepts a package as a parameter, and
+     returns a boolean. The following example configuration accepts a package
+     and always returns false:
+<programlisting>
+{
+  allowUnfreePredicate = (pkg: false);
+}
+</programlisting>
+    </para>
+    <para>
+     For a more useful example, try the following. This configuration
+     only allows unfree packages named flash player and visual studio
+     code:
+<programlisting>
+{
+  allowUnfreePredicate = (pkg: builtins.elem (builtins.parseDrvName pkg.name).name [ "flashplayer" "vscode" ]);
+}
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     It is also possible to whitelist and blacklist licenses that are
+     specifically acceptable or not acceptable, using
+     <literal>whitelistedLicenses</literal> and
+     <literal>blacklistedLicenses</literal>, respectively.
+    </para>
+    <para>
+     The following example configuration whitelists the licenses
+     <literal>amd</literal> and <literal>wtfpl</literal>:
+<programlisting>
+{
+  whitelistedLicenses = with stdenv.lib.licenses; [ amd wtfpl ];
+}
+</programlisting>
+    </para>
+    <para>
+     The following example configuration blacklists the <literal>gpl3</literal>
+     and <literal>agpl3</literal> licenses:
+<programlisting>
+{
+  blacklistedLicenses = with stdenv.lib.licenses; [ agpl3 gpl3 ];
+}
+</programlisting>
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <para>
+   A complete list of licenses can be found in the file
+   <filename>lib/licenses.nix</filename> of the nixpkgs tree.
+  </para>
+ </section>
+ <section xml:id="sec-allow-insecure">
+  <title>Installing insecure packages</title>
+
+  <para>
+   There are several ways to tweak how Nix handles a package which has been
+   marked as insecure.
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     To temporarily allow all insecure packages, you can use an environment
+     variable for a single invocation of the nix tools:
+<programlisting>$ export NIXPKGS_ALLOW_INSECURE=1</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     It is possible to permanently allow individual insecure packages, while
+     still blocking other insecure packages by default using the
+     <literal>permittedInsecurePackages</literal> configuration option in the
+     user configuration file.
+    </para>
+    <para>
+     The following example configuration permits the installation of the
+     hypothetically insecure package <literal>hello</literal>, version
+     <literal>1.2.3</literal>:
+<programlisting>
+{
+  permittedInsecurePackages = [
+    "hello-1.2.3"
+  ];
+}
+</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     It is also possible to create a custom policy around which insecure
+     packages to allow and deny, by overriding the
+     <literal>allowInsecurePredicate</literal> configuration option.
+    </para>
+    <para>
+     The <literal>allowInsecurePredicate</literal> option is a function which
+     accepts a package and returns a boolean, much like
+     <literal>allowUnfreePredicate</literal>.
+    </para>
+    <para>
+     The following configuration example only allows insecure packages with
+     very short names:
+<programlisting>
+{
+  allowInsecurePredicate = (pkg: (builtins.stringLength (builtins.parseDrvName pkg.name).name) &lt;= 5);
+}
+</programlisting>
+    </para>
+    <para>
+     Note that <literal>permittedInsecurePackages</literal> is only checked if
+     <literal>allowInsecurePredicate</literal> is not specified.
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+<!--============================================================-->
+ <section xml:id="sec-modify-via-packageOverrides">
+  <title>Modify packages via <literal>packageOverrides</literal></title>
+
+  <para>
+   You can define a function called <varname>packageOverrides</varname> in your
+   local <filename>~/.config/nixpkgs/config.nix</filename> to override Nix
+   packages. It must be a function that takes pkgs as an argument and returns a
+   modified set of packages.
+<programlisting>
+{
+  packageOverrides = pkgs: rec {
+    foo = pkgs.foo.override { ... };
+  };
+}
+</programlisting>
+  </para>
+ </section>
+ <section xml:id="sec-declarative-package-management">
+  <title>Declarative Package Management</title>
+
+  <section xml:id="sec-building-environment">
+   <title>Build an environment</title>
+
+   <para>
+    Using <literal>packageOverrides</literal>, it is possible to manage
+    packages declaratively. This means that we can list all of our desired
+    packages within a declarative Nix expression. For example, to have
+    <literal>aspell</literal>, <literal>bc</literal>,
+    <literal>ffmpeg</literal>, <literal>coreutils</literal>,
+    <literal>gdb</literal>, <literal>nixUnstable</literal>,
+    <literal>emscripten</literal>, <literal>jq</literal>,
+    <literal>nox</literal>, and <literal>silver-searcher</literal>, we could
+    use the following in <filename>~/.config/nixpkgs/config.nix</filename>:
+   </para>
+
+<screen>
+{
+  packageOverrides = pkgs: with pkgs; {
+    myPackages = pkgs.buildEnv {
+      name = "my-packages";
+      paths = [ aspell bc coreutils gdb ffmpeg nixUnstable emscripten jq nox silver-searcher ];
+    };
+  };
+}
+</screen>
+
+   <para>
+    To install it into our environment, you can just run <literal>nix-env -iA
+    nixpkgs.myPackages</literal>. If you want to load the packages to be built
+    from a working copy of <literal>nixpkgs</literal> you just run
+    <literal>nix-env -f. -iA myPackages</literal>. To explore what's been
+    installed, just look through <filename>~/.nix-profile/</filename>. You can
+    see that a lot of stuff has been installed. Some of this stuff is useful
+    some of it isn't. Let's tell Nixpkgs to only link the stuff that we want:
+   </para>
+
+<screen>
+{
+  packageOverrides = pkgs: with pkgs; {
+    myPackages = pkgs.buildEnv {
+      name = "my-packages";
+      paths = [ aspell bc coreutils gdb ffmpeg nixUnstable emscripten jq nox silver-searcher ];
+      pathsToLink = [ "/share" "/bin" ];
+    };
+  };
+}
+</screen>
+
+   <para>
+    <literal>pathsToLink</literal> tells Nixpkgs to only link the paths listed
+    which gets rid of the extra stuff in the profile. <filename>/bin</filename>
+    and <filename>/share</filename> are good defaults for a user environment,
+    getting rid of the clutter. If you are running on Nix on MacOS, you may
+    want to add another path as well, <filename>/Applications</filename>, that
+    makes GUI apps available.
+   </para>
+  </section>
+
+  <section xml:id="sec-getting-documentation">
+   <title>Getting documentation</title>
+
+   <para>
+    After building that new environment, look through
+    <filename>~/.nix-profile</filename> to make sure everything is there that
+    we wanted. Discerning readers will note that some files are missing. Look
+    inside <filename>~/.nix-profile/share/man/man1/</filename> to verify this.
+    There are no man pages for any of the Nix tools! This is because some
+    packages like Nix have multiple outputs for things like documentation (see
+    section 4). Let's make Nix install those as well.
+   </para>
+
+<screen>
+{
+  packageOverrides = pkgs: with pkgs; {
+    myPackages = pkgs.buildEnv {
+      name = "my-packages";
+      paths = [ aspell bc coreutils ffmpeg nixUnstable emscripten jq nox silver-searcher ];
+      pathsToLink = [ "/share/man" "/share/doc" "/bin" ];
+      extraOutputsToInstall = [ "man" "doc" ];
+    };
+  };
+}
+</screen>
+
+   <para>
+    This provides us with some useful documentation for using our packages.
+    However, if we actually want those manpages to be detected by man, we need
+    to set up our environment. This can also be managed within Nix expressions.
+   </para>
+
+<screen>
+{
+  packageOverrides = pkgs: with pkgs; rec {
+    myProfile = writeText "my-profile" ''
+      export PATH=$HOME/.nix-profile/bin:/nix/var/nix/profiles/default/bin:/sbin:/bin:/usr/sbin:/usr/bin
+      export MANPATH=$HOME/.nix-profile/share/man:/nix/var/nix/profiles/default/share/man:/usr/share/man
+    '';
+    myPackages = pkgs.buildEnv {
+      name = "my-packages";
+      paths = [
+        (runCommand "profile" {} ''
+          mkdir -p $out/etc/profile.d
+          cp ${myProfile} $out/etc/profile.d/my-profile.sh
+        '')
+        aspell
+        bc
+        coreutils
+        ffmpeg
+        man
+        nixUnstable
+        emscripten
+        jq
+        nox
+        silver-searcher
+      ];
+      pathsToLink = [ "/share/man" "/share/doc" "/bin" "/etc" ];
+      extraOutputsToInstall = [ "man" "doc" ];
+    };
+  };
+}
+</screen>
+
+   <para>
+    For this to work fully, you must also have this script sourced when you are
+    logged in. Try adding something like this to your
+    <filename>~/.profile</filename> file:
+   </para>
+
+<screen>
+#!/bin/sh
+if [ -d $HOME/.nix-profile/etc/profile.d ]; then
+  for i in $HOME/.nix-profile/etc/profile.d/*.sh; do
+    if [ -r $i ]; then
+      . $i
+    fi
+  done
+fi
+</screen>
+
+   <para>
+    Now just run <literal>source $HOME/.profile</literal> and you can starting
+    loading man pages from your environent.
+   </para>
+  </section>
+
+  <section xml:id="sec-gnu-info-setup">
+   <title>GNU info setup</title>
+
+   <para>
+    Configuring GNU info is a little bit trickier than man pages. To work
+    correctly, info needs a database to be generated. This can be done with
+    some small modifications to our environment scripts.
+   </para>
+
+<screen>
+{
+  packageOverrides = pkgs: with pkgs; rec {
+    myProfile = writeText "my-profile" ''
+      export PATH=$HOME/.nix-profile/bin:/nix/var/nix/profiles/default/bin:/sbin:/bin:/usr/sbin:/usr/bin
+      export MANPATH=$HOME/.nix-profile/share/man:/nix/var/nix/profiles/default/share/man:/usr/share/man
+      export INFOPATH=$HOME/.nix-profile/share/info:/nix/var/nix/profiles/default/share/info:/usr/share/info
+    '';
+    myPackages = pkgs.buildEnv {
+      name = "my-packages";
+      paths = [
+        (runCommand "profile" {} ''
+          mkdir -p $out/etc/profile.d
+          cp ${myProfile} $out/etc/profile.d/my-profile.sh
+        '')
+        aspell
+        bc
+        coreutils
+        ffmpeg
+        man
+        nixUnstable
+        emscripten
+        jq
+        nox
+        silver-searcher
+        texinfoInteractive
+      ];
+      pathsToLink = [ "/share/man" "/share/doc" "/share/info" "/bin" "/etc" ];
+      extraOutputsToInstall = [ "man" "doc" "info" ];
+      postBuild = ''
+        if [ -x $out/bin/install-info -a -w $out/share/info ]; then
+          shopt -s nullglob
+          for i in $out/share/info/*.info $out/share/info/*.info.gz; do
+              $out/bin/install-info $i $out/share/info/dir
+          done
+        fi
+      '';
+    };
+  };
+}
+</screen>
+
+   <para>
+    <literal>postBuild</literal> tells Nixpkgs to run a command after building
+    the environment. In this case, <literal>install-info</literal> adds the
+    installed info pages to <literal>dir</literal> which is GNU info's default
+    root node. Note that <literal>texinfoInteractive</literal> is added to the
+    environment to give the <literal>install-info</literal> command.
+   </para>
+  </section>
+ </section>
+</chapter>
diff --git a/nixpkgs/doc/contributing.xml b/nixpkgs/doc/contributing.xml
new file mode 100644
index 000000000000..d28442b7a2c6
--- /dev/null
+++ b/nixpkgs/doc/contributing.xml
@@ -0,0 +1,35 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-contributing">
+ <title>Contributing to this documentation</title>
+ <para>
+  The DocBook sources of the Nixpkgs manual are in the
+  <filename
+xlink:href="https://github.com/NixOS/nixpkgs/tree/master/doc">doc</filename>
+  subdirectory of the Nixpkgs repository.
+ </para>
+ <para>
+  You can quickly check your edits with <command>make</command>:
+ </para>
+<screen>
+  $ cd /path/to/nixpkgs/doc
+  $ nix-shell
+  [nix-shell]$ make
+</screen>
+ <para>
+  If you experience problems, run <command>make debug</command> to help
+  understand the docbook errors.
+ </para>
+ <para>
+  After making modifications to the manual, it's important to build it before
+  committing. You can do that as follows:
+<screen>
+  $ cd /path/to/nixpkgs/doc
+  $ nix-shell
+  [nix-shell]$ make clean
+  [nix-shell]$ nix-build .
+</screen>
+  If the build succeeds, the manual will be in
+  <filename>./result/share/doc/nixpkgs/manual.html</filename>.
+ </para>
+</chapter>
diff --git a/nixpkgs/doc/cross-compilation.xml b/nixpkgs/doc/cross-compilation.xml
new file mode 100644
index 000000000000..40cf11304eae
--- /dev/null
+++ b/nixpkgs/doc/cross-compilation.xml
@@ -0,0 +1,468 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-cross">
+ <title>Cross-compilation</title>
+ <section xml:id="sec-cross-intro">
+  <title>Introduction</title>
+
+  <para>
+   "Cross-compilation" means compiling a program on one machine for another type
+   of machine. For example, a typical use of cross-compilation is to compile
+   programs for embedded devices. These devices often don't have the computing
+   power and memory to compile their own programs. One might think that
+   cross-compilation is a fairly niche concern. However, there are significant
+   advantages to rigorously distinguishing between build-time and run-time
+   environments! This applies even when one is developing and deploying on the
+   same machine. Nixpkgs is increasingly adopting the opinion that packages
+   should be written with cross-compilation in mind, and nixpkgs should evaluate
+   in a similar way (by minimizing cross-compilation-specific special cases)
+   whether or not one is cross-compiling.
+  </para>
+
+  <para>
+   This chapter will be organized in three parts. First, it will describe the
+   basics of how to package software in a way that supports cross-compilation.
+   Second, it will describe how to use Nixpkgs when cross-compiling. Third, it
+   will describe the internal infrastructure supporting cross-compilation.
+  </para>
+ </section>
+<!--============================================================-->
+ <section xml:id="sec-cross-packaging">
+  <title>Packaging in a cross-friendly manner</title>
+
+  <section xml:id="sec-cross-platform-parameters">
+   <title>Platform parameters</title>
+
+   <para>
+     Nixpkgs follows the <link
+     xlink:href="https://gcc.gnu.org/onlinedocs/gccint/Configure-Terms.html">conventions
+     of GNU autoconf</link>. We distinguish between 3 types of platforms when
+     building a derivation: <wordasword>build</wordasword>,
+     <wordasword>host</wordasword>, and <wordasword>target</wordasword>. In
+     summary, <wordasword>build</wordasword> is the platform on which a package
+     is being built, <wordasword>host</wordasword> is the platform on which it
+     will run. The third attribute, <wordasword>target</wordasword>, is relevant
+     only for certain specific compilers and build tools.
+   </para>
+
+   <para>
+    In Nixpkgs, these three platforms are defined as attribute sets under the
+    names <literal>buildPlatform</literal>, <literal>hostPlatform</literal>,
+    and <literal>targetPlatform</literal>. They are always defined as
+    attributes in the standard environment. That means one can access them
+    like:
+<programlisting>{ stdenv, fooDep, barDep, .. }: ...stdenv.buildPlatform...</programlisting>
+    .
+   </para>
+
+   <variablelist>
+    <varlistentry>
+     <term>
+      <varname>buildPlatform</varname>
+     </term>
+     <listitem>
+      <para>
+       The "build platform" is the platform on which a package is built. Once
+       someone has a built package, or pre-built binary package, the build
+       platform should not matter and can be ignored.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>hostPlatform</varname>
+     </term>
+     <listitem>
+      <para>
+       The "host platform" is the platform on which a package will be run. This
+       is the simplest platform to understand, but also the one with the worst
+       name.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>targetPlatform</varname>
+     </term>
+     <listitem>
+      <para>
+       The "target platform" attribute is, unlike the other two attributes, not
+       actually fundamental to the process of building software. Instead, it is
+       only relevant for compatibility with building certain specific compilers
+       and build tools. It can be safely ignored for all other packages.
+      </para>
+      <para>
+       The build process of certain compilers is written in such a way that the
+       compiler resulting from a single build can itself only produce binaries
+       for a single platform. The task of specifying this single "target
+       platform" is thus pushed to build time of the compiler. The root cause of
+       this that the compiler (which will be run on the host) and the standard
+       library/runtime (which will be run on the target) are built by a single
+       build process.
+      </para>
+      <para>
+       There is no fundamental need to think about a single target ahead of
+       time like this. If the tool supports modular or pluggable backends, both
+       the need to specify the target at build time and the constraint of
+       having only a single target disappear. An example of such a tool is
+       LLVM.
+      </para>
+      <para>
+       Although the existence of a "target platfom" is arguably a historical
+       mistake, it is a common one: examples of tools that suffer from it are
+       GCC, Binutils, GHC and Autoconf. Nixpkgs tries to avoid sharing in the
+       mistake where possible. Still, because the concept of a target platform
+       is so ingrained, it is best to support it as is.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+
+   <para>
+    The exact schema these fields follow is a bit ill-defined due to a long and
+    convoluted evolution, but this is slowly being cleaned up. You can see
+    examples of ones used in practice in
+    <literal>lib.systems.examples</literal>; note how they are not all very
+    consistent. For now, here are few fields can count on them containing:
+   </para>
+
+   <variablelist>
+    <varlistentry>
+     <term>
+      <varname>system</varname>
+     </term>
+     <listitem>
+      <para>
+       This is a two-component shorthand for the platform. Examples of this
+       would be "x86_64-darwin" and "i686-linux"; see
+       <literal>lib.systems.doubles</literal> for more. The first component
+       corresponds to the CPU architecture of the platform and the second to the
+       operating system of the platform (<literal>[cpu]-[os]</literal>). This
+       format has built-in support in Nix, such as the
+       <varname>builtins.currentSystem</varname> impure string.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>config</varname>
+     </term>
+     <listitem>
+      <para>
+       This is a 3- or 4- component shorthand for the platform. Examples of this
+       would be <literal>x86_64-unknown-linux-gnu</literal> and
+       <literal>aarch64-apple-darwin14</literal>. This is a standard format
+       called the "LLVM target triple", as they are pioneered by LLVM. In the
+       4-part form, this corresponds to
+       <literal>[cpu]-[vendor]-[os]-[abi]</literal>. This format is strictly
+       more informative than the "Nix host double", as the previous format could
+       analogously be termed. This needs a better name than
+       <varname>config</varname>!
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>parsed</varname>
+     </term>
+     <listitem>
+      <para>
+       This is a Nix representation of a parsed LLVM target triple
+       with white-listed components. This can be specified directly,
+       or actually parsed from the <varname>config</varname>. See
+       <literal>lib.systems.parse</literal> for the exact
+       representation.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>libc</varname>
+     </term>
+     <listitem>
+      <para>
+       This is a string identifying the standard C library used. Valid
+       identifiers include "glibc" for GNU libc, "libSystem" for Darwin's
+       Libsystem, and "uclibc" for µClibc. It should probably be refactored to
+       use the module system, like <varname>parse</varname>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>is*</varname>
+     </term>
+     <listitem>
+      <para>
+       These predicates are defined in <literal>lib.systems.inspect</literal>,
+       and slapped onto every platform. They are superior to the ones in
+       <varname>stdenv</varname> as they force the user to be explicit about
+       which platform they are inspecting. Please use these instead of those.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>platform</varname>
+     </term>
+     <listitem>
+      <para>
+       This is, quite frankly, a dumping ground of ad-hoc settings (it's an
+       attribute set). See <literal>lib.systems.platforms</literal> for
+       examples—there's hopefully one in there that will work verbatim for
+       each platform that is working. Please help us triage these flags and
+       give them better homes!
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="sec-cross-specifying-dependencies">
+   <title>Specifying Dependencies</title>
+
+   <para>
+    In this section we explore the relationship between both runtime and
+    build-time dependencies and the 3 Autoconf platforms.
+   </para>
+
+   <para>
+    A runtime dependency between 2 packages implies that between them both the
+    host and target platforms match. This is directly implied by the meaning of
+    "host platform" and "runtime dependency": The package dependency exists
+    while both packages are running on a single host platform.
+   </para>
+
+   <para>
+    A build time dependency, however, implies a shift in platforms between the
+    depending package and the depended-on package. The meaning of a build time
+    dependency is that to build the depending package we need to be able to run
+    the depended-on's package. The depending package's build platform is
+    therefore equal to the depended-on package's host platform. Analogously,
+    the depending package's host platform is equal to the depended-on package's
+    target platform.
+   </para>
+
+   <para>
+    In this manner, given the 3 platforms for one package, we can determine the
+    three platforms for all its transitive dependencies. This is the most
+    important guiding principle behind cross-compilation with Nixpkgs, and will
+    be called the <wordasword>sliding window principle</wordasword>.
+   </para>
+
+   <para>
+    Some examples will make this clearer. If a package is being built with a
+    <literal>(build, host, target)</literal> platform triple of <literal>(foo,
+    bar, bar)</literal>, then its build-time dependencies would have a triple of
+    <literal>(foo, foo, bar)</literal>, and <emphasis>those packages'</emphasis>
+    build-time dependencies would have a triple of <literal>(foo, foo,
+    foo)</literal>. In other words, it should take two "rounds" of following
+    build-time dependency edges before one reaches a fixed point where, by the
+    sliding window principle, the platform triple no longer changes. Indeed,
+    this happens with cross-compilation, where only rounds of native
+    dependencies starting with the second necessarily coincide with native
+    packages.
+   </para>
+
+   <note>
+    <para>
+     The depending package's target platform is unconstrained by the sliding
+     window principle, which makes sense in that one can in principle build
+     cross compilers targeting arbitrary platforms.
+    </para>
+   </note>
+
+   <para>
+    How does this work in practice? Nixpkgs is now structured so that build-time
+    dependencies are taken from <varname>buildPackages</varname>, whereas
+    run-time dependencies are taken from the top level attribute set. For
+    example, <varname>buildPackages.gcc</varname> should be used at build-time,
+    while <varname>gcc</varname> should be used at run-time. Now, for most of
+    Nixpkgs's history, there was no <varname>buildPackages</varname>, and most
+    packages have not been refactored to use it explicitly. Instead, one can use
+    the six (<emphasis>gasp</emphasis>) attributes used for specifying
+    dependencies as documented in <xref linkend="ssec-stdenv-dependencies"/>. We
+    "splice" together the run-time and build-time package sets with
+    <varname>callPackage</varname>, and then <varname>mkDerivation</varname> for
+    each of four attributes pulls the right derivation out. This splicing can be
+    skipped when not cross-compiling as the package sets are the same, but is a
+    bit slow for cross-compiling. Because of this, a best-of-both-worlds
+    solution is in the works with no splicing or explicit access of
+    <varname>buildPackages</varname> needed. For now, feel free to use either
+    method.
+   </para>
+
+   <note>
+    <para>
+     There is also a "backlink" <varname>targetPackages</varname>, yielding a
+     package set whose <varname>buildPackages</varname> is the current package
+     set. This is a hack, though, to accommodate compilers with lousy build
+     systems. Please do not use this unless you are absolutely sure you are
+     packaging such a compiler and there is no other way.
+    </para>
+   </note>
+  </section>
+
+  <section xml:id="sec-cross-cookbook">
+   <title>Cross packaging cookbook</title>
+
+   <para>
+    Some frequently encountered problems when packaging for cross-compilation
+    should be answered here. Ideally, the information above is exhaustive, so
+    this section cannot provide any new information, but it is ludicrous and
+    cruel to expect everyone to spend effort working through the interaction of
+    many features just to figure out the same answer to the same common problem.
+    Feel free to add to this list!
+   </para>
+
+   <qandaset>
+    <qandaentry xml:id="cross-qa-build-c-program-in-build-environment">
+     <question>
+      <para>
+       What if my package's build system needs to build a C program to be run
+       under the build environment?
+      </para>
+     </question>
+     <answer>
+      <para>
+<programlisting>depsBuildBuild = [ buildPackages.stdenv.cc ];</programlisting>
+       Add it to your <function>mkDerivation</function> invocation.
+      </para>
+     </answer>
+    </qandaentry>
+    <qandaentry xml:id="cross-qa-fails-to-find-ar">
+     <question>
+      <para>
+       My package fails to find <command>ar</command>.
+      </para>
+     </question>
+     <answer>
+      <para>
+       Many packages assume that an unprefixed <command>ar</command> is
+       available, but Nix doesn't provide one. It only provides a prefixed one,
+       just as it only does for all the other binutils programs. It may be
+       necessary to patch the package to fix the build system to use a prefixed
+       `ar`.
+      </para>
+     </answer>
+    </qandaentry>
+    <qandaentry xml:id="cross-testsuite-runs-host-code">
+     <question>
+      <para>
+       My package's testsuite needs to run host platform code.
+      </para>
+     </question>
+     <answer>
+      <para>
+<programlisting>doCheck = stdenv.hostPlatform != stdenv.buildPlatfrom;</programlisting>
+       Add it to your <function>mkDerivation</function> invocation.
+      </para>
+     </answer>
+    </qandaentry>
+   </qandaset>
+  </section>
+ </section>
+<!--============================================================-->
+ <section xml:id="sec-cross-usage">
+  <title>Cross-building packages</title>
+
+  <para>
+   Nixpkgs can be instantiated with <varname>localSystem</varname> alone, in
+   which case there is no cross-compiling and everything is built by and for
+   that system, or also with <varname>crossSystem</varname>, in which case
+   packages run on the latter, but all building happens on the former. Both
+   parameters take the same schema as the 3 (build, host, and target) platforms
+   defined in the previous section. As mentioned above,
+   <literal>lib.systems.examples</literal> has some platforms which are used as
+   arguments for these parameters in practice. You can use them
+   programmatically, or on the command line:
+<programlisting>
+nix-build &lt;nixpkgs&gt; --arg crossSystem '(import &lt;nixpkgs/lib&gt;).systems.examples.fooBarBaz' -A whatever</programlisting>
+  </para>
+
+  <note>
+   <para>
+    Eventually we would like to make these platform examples an unnecessary
+    convenience so that
+<programlisting>
+nix-build &lt;nixpkgs&gt; --arg crossSystem '{ config = "&lt;arch&gt;-&lt;os&gt;-&lt;vendor&gt;-&lt;abi&gt;"; }' -A whatever</programlisting>
+    works in the vast majority of cases. The problem today is dependencies on
+    other sorts of configuration which aren't given proper defaults. We rely on
+    the examples to crudely to set those configuration parameters in some
+    vaguely sane manner on the users behalf. Issue
+    <link xlink:href="https://github.com/NixOS/nixpkgs/issues/34274">#34274</link>
+    tracks this inconvenience along with its root cause in crufty configuration
+    options.
+   </para>
+  </note>
+
+  <para>
+   While one is free to pass both parameters in full, there's a lot of logic to
+   fill in missing fields. As discussed in the previous section, only one of
+   <varname>system</varname>, <varname>config</varname>, and
+   <varname>parsed</varname> is needed to infer the other two. Additionally,
+   <varname>libc</varname> will be inferred from <varname>parse</varname>.
+   Finally, <literal>localSystem.system</literal> is also
+   <emphasis>impurely</emphasis> inferred based on the platform evaluation
+   occurs. This means it is often not necessary to pass
+   <varname>localSystem</varname> at all, as in the command-line example in the
+   previous paragraph.
+  </para>
+
+  <note>
+   <para>
+    Many sources (manual, wiki, etc) probably mention passing
+    <varname>system</varname>, <varname>platform</varname>, along with the
+    optional <varname>crossSystem</varname> to nixpkgs: <literal>import
+    &lt;nixpkgs&gt; { system = ..; platform = ..; crossSystem = ..;
+    }</literal>. Passing those two instead of <varname>localSystem</varname> is
+    still supported for compatibility, but is discouraged. Indeed, much of the
+    inference we do for these parameters is motivated by compatibility as much
+    as convenience.
+   </para>
+  </note>
+
+  <para>
+   One would think that <varname>localSystem</varname> and
+   <varname>crossSystem</varname> overlap horribly with the three
+   <varname>*Platforms</varname> (<varname>buildPlatform</varname>,
+   <varname>hostPlatform,</varname> and <varname>targetPlatform</varname>; see
+   <varname>stage.nix</varname> or the manual). Actually, those identifiers are
+   purposefully not used here to draw a subtle but important distinction: While
+   the granularity of having 3 platforms is necessary to properly *build*
+   packages, it is overkill for specifying the user's *intent* when making a
+   build plan or package set. A simple "build vs deploy" dichotomy is adequate:
+   the sliding window principle described in the previous section shows how to
+   interpolate between the these two "end points" to get the 3 platform triple
+   for each bootstrapping stage. That means for any package a given package set,
+   even those not bound on the top level but only reachable via dependencies or
+   <varname>buildPackages</varname>, the three platforms will be defined as one
+   of <varname>localSystem</varname> or <varname>crossSystem</varname>, with the
+   former replacing the latter as one traverses build-time dependencies. A last
+   simple difference is that <varname>crossSystem</varname> should be null when
+   one doesn't want to cross-compile, while the <varname>*Platform</varname>s
+   are always non-null. <varname>localSystem</varname> is always non-null.
+  </para>
+ </section>
+<!--============================================================-->
+ <section xml:id="sec-cross-infra">
+  <title>Cross-compilation infrastructure</title>
+
+  <para>
+   To be written.
+  </para>
+
+  <note>
+   <para>
+    If one explores Nixpkgs, they will see derivations with names like
+    <literal>gccCross</literal>. Such <literal>*Cross</literal> derivations is a
+    holdover from before we properly distinguished between the host and target
+    platforms—the derivation with "Cross" in the name covered the <literal>build
+    = host != target</literal> case, while the other covered the <literal>host =
+    target</literal>, with build platform the same or not based on whether one
+    was using its <literal>.nativeDrv</literal> or <literal>.crossDrv</literal>.
+    This ugliness will disappear soon.
+   </para>
+  </note>
+ </section>
+</chapter>
diff --git a/nixpkgs/doc/default.nix b/nixpkgs/doc/default.nix
new file mode 100644
index 000000000000..98b4b92be524
--- /dev/null
+++ b/nixpkgs/doc/default.nix
@@ -0,0 +1,50 @@
+{ pkgs ? (import ./.. { }), nixpkgs ? { }}:
+let
+  lib = pkgs.lib;
+  locationsXml = import ./lib-function-locations.nix { inherit pkgs nixpkgs; };
+in
+pkgs.stdenv.mkDerivation {
+  name = "nixpkgs-manual";
+
+  buildInputs = with pkgs; [ pandoc libxml2 libxslt zip jing  xmlformat ];
+
+  src = ./.;
+
+  # Hacking on these variables? Make sure to close and open
+  # nix-shell between each test, maybe even:
+  # $ nix-shell --run "make clean all"
+  # otherwise they won't reapply :)
+  HIGHLIGHTJS = pkgs.documentation-highlighter;
+  XSL = "${pkgs.docbook_xsl_ns}/xml/xsl";
+  RNG = "${pkgs.docbook5}/xml/rng/docbook/docbook.rng";
+  XMLFORMAT_CONFIG = ../nixos/doc/xmlformat.conf;
+  xsltFlags = lib.concatStringsSep " " [
+    "--param section.autolabel 1"
+    "--param section.label.includes.component.label 1"
+    "--stringparam html.stylesheet 'style.css overrides.css highlightjs/mono-blue.css'"
+    "--stringparam html.script './highlightjs/highlight.pack.js ./highlightjs/loader.js'"
+    "--param xref.with.number.and.title 1"
+    "--param toc.section.depth 3"
+    "--stringparam admon.style ''"
+    "--stringparam callout.graphics.extension .svg"
+  ];
+
+  postPatch = ''
+    rm -rf ./functions/library/locations.xml
+    ln -s ${locationsXml} ./functions/library/locations.xml
+    echo ${lib.version} > .version
+  '';
+
+  installPhase = ''
+    dest="$out/share/doc/nixpkgs"
+    mkdir -p "$(dirname "$dest")"
+    mv out/html "$dest"
+    mv "$dest/index.html" "$dest/manual.html"
+
+    mv out/epub/manual.epub "$dest/nixpkgs-manual.epub"
+
+    mkdir -p $out/nix-support/
+    echo "doc manual $dest manual.html" >> $out/nix-support/hydra-build-products
+    echo "doc manual $dest nixpkgs-manual.epub" >> $out/nix-support/hydra-build-products
+  '';
+}
diff --git a/nixpkgs/doc/functions.xml b/nixpkgs/doc/functions.xml
new file mode 100644
index 000000000000..4193bb49f77a
--- /dev/null
+++ b/nixpkgs/doc/functions.xml
@@ -0,0 +1,17 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="chap-functions">
+ <title>Functions reference</title>
+ <para>
+  The nixpkgs repository has several utility functions to manipulate Nix
+  expressions.
+ </para>
+ <xi:include href="functions/library.xml" />
+ <xi:include href="functions/overrides.xml" />
+ <xi:include href="functions/generators.xml" />
+ <xi:include href="functions/debug.xml" />
+ <xi:include href="functions/fhs-environments.xml" />
+ <xi:include href="functions/shell.xml" />
+ <xi:include href="functions/dockertools.xml" />
+</chapter>
diff --git a/nixpkgs/doc/functions/debug.xml b/nixpkgs/doc/functions/debug.xml
new file mode 100644
index 000000000000..c6b3611eea53
--- /dev/null
+++ b/nixpkgs/doc/functions/debug.xml
@@ -0,0 +1,21 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-debug">
+ <title>Debugging Nix Expressions</title>
+
+ <para>
+  Nix is a unityped, dynamic language, this means every value can potentially
+  appear anywhere. Since it is also non-strict, evaluation order and what
+  ultimately is evaluated might surprise you. Therefore it is important to be
+  able to debug nix expressions.
+ </para>
+
+ <para>
+  In the <literal>lib/debug.nix</literal> file you will find a number of
+  functions that help (pretty-)printing values while evaluation is runnnig. You
+  can even specify how deep these values should be printed recursively, and
+  transform them on the fly. Please consult the docstrings in
+  <literal>lib/debug.nix</literal> for usage information.
+ </para>
+</section>
diff --git a/nixpkgs/doc/functions/dockertools.xml b/nixpkgs/doc/functions/dockertools.xml
new file mode 100644
index 000000000000..501f46a967c3
--- /dev/null
+++ b/nixpkgs/doc/functions/dockertools.xml
@@ -0,0 +1,564 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-pkgs-dockerTools">
+ <title>pkgs.dockerTools</title>
+
+ <para>
+  <varname>pkgs.dockerTools</varname> is a set of functions for creating and
+  manipulating Docker images according to the
+  <link xlink:href="https://github.com/moby/moby/blob/master/image/spec/v1.2.md#docker-image-specification-v120">
+  Docker Image Specification v1.2.0 </link>. Docker itself is not used to
+  perform any of the operations done by these functions.
+ </para>
+
+ <warning>
+  <para>
+   The <varname>dockerTools</varname> API is unstable and may be subject to
+   backwards-incompatible changes in the future.
+  </para>
+ </warning>
+
+ <section xml:id="ssec-pkgs-dockerTools-buildImage">
+  <title>buildImage</title>
+
+  <para>
+   This function is analogous to the <command>docker build</command> command,
+   in that can used to build a Docker-compatible repository tarball containing
+   a single image with one or multiple layers. As such, the result is suitable
+   for being loaded in Docker with <command>docker load</command>.
+  </para>
+
+  <para>
+   The parameters of <varname>buildImage</varname> with relative example values
+   are described below:
+  </para>
+
+  <example xml:id='ex-dockerTools-buildImage'>
+   <title>Docker build</title>
+<programlisting>
+buildImage {
+  name = "redis"; <co xml:id='ex-dockerTools-buildImage-1' />
+  tag = "latest"; <co xml:id='ex-dockerTools-buildImage-2' />
+
+  fromImage = someBaseImage; <co xml:id='ex-dockerTools-buildImage-3' />
+  fromImageName = null; <co xml:id='ex-dockerTools-buildImage-4' />
+  fromImageTag = "latest"; <co xml:id='ex-dockerTools-buildImage-5' />
+
+  contents = pkgs.redis; <co xml:id='ex-dockerTools-buildImage-6' />
+  runAsRoot = '' <co xml:id='ex-dockerTools-buildImage-runAsRoot' />
+    #!${stdenv.shell}
+    mkdir -p /data
+  '';
+
+  config = { <co xml:id='ex-dockerTools-buildImage-8' />
+    Cmd = [ "/bin/redis-server" ];
+    WorkingDir = "/data";
+    Volumes = {
+      "/data" = {};
+    };
+  };
+}
+</programlisting>
+  </example>
+
+  <para>
+   The above example will build a Docker image <literal>redis/latest</literal>
+   from the given base image. Loading and running this image in Docker results
+   in <literal>redis-server</literal> being started automatically.
+  </para>
+
+  <calloutlist>
+   <callout arearefs='ex-dockerTools-buildImage-1'>
+    <para>
+     <varname>name</varname> specifies the name of the resulting image. This is
+     the only required argument for <varname>buildImage</varname>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-2'>
+    <para>
+     <varname>tag</varname> specifies the tag of the resulting image. By
+     default it's <literal>null</literal>, which indicates that the nix output
+     hash will be used as tag.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-3'>
+    <para>
+     <varname>fromImage</varname> is the repository tarball containing the base
+     image. It must be a valid Docker image, such as exported by
+     <command>docker save</command>. By default it's <literal>null</literal>,
+     which can be seen as equivalent to <literal>FROM scratch</literal> of a
+     <filename>Dockerfile</filename>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-4'>
+    <para>
+     <varname>fromImageName</varname> can be used to further specify the base
+     image within the repository, in case it contains multiple images. By
+     default it's <literal>null</literal>, in which case
+     <varname>buildImage</varname> will peek the first image available in the
+     repository.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-5'>
+    <para>
+     <varname>fromImageTag</varname> can be used to further specify the tag of
+     the base image within the repository, in case an image contains multiple
+     tags. By default it's <literal>null</literal>, in which case
+     <varname>buildImage</varname> will peek the first tag available for the
+     base image.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-6'>
+    <para>
+     <varname>contents</varname> is a derivation that will be copied in the new
+     layer of the resulting image. This can be similarly seen as <command>ADD
+     contents/ /</command> in a <filename>Dockerfile</filename>. By default
+     it's <literal>null</literal>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-runAsRoot'>
+    <para>
+     <varname>runAsRoot</varname> is a bash script that will run as root in an
+     environment that overlays the existing layers of the base image with the
+     new resulting layer, including the previously copied
+     <varname>contents</varname> derivation. This can be similarly seen as
+     <command>RUN ...</command> in a <filename>Dockerfile</filename>.
+     <note>
+      <para>
+       Using this parameter requires the <literal>kvm</literal> device to be
+       available.
+      </para>
+     </note>
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-buildImage-8'>
+    <para>
+     <varname>config</varname> is used to specify the configuration of the
+     containers that will be started off the built image in Docker. The
+     available options are listed in the
+     <link xlink:href="https://github.com/moby/moby/blob/master/image/spec/v1.2.md#image-json-field-descriptions">
+     Docker Image Specification v1.2.0 </link>.
+    </para>
+   </callout>
+  </calloutlist>
+
+  <para>
+   After the new layer has been created, its closure (to which
+   <varname>contents</varname>, <varname>config</varname> and
+   <varname>runAsRoot</varname> contribute) will be copied in the layer itself.
+   Only new dependencies that are not already in the existing layers will be
+   copied.
+  </para>
+
+  <para>
+   At the end of the process, only one new single layer will be produced and
+   added to the resulting image.
+  </para>
+
+  <para>
+   The resulting repository will only list the single image
+   <varname>image/tag</varname>. In the case of
+   <xref linkend='ex-dockerTools-buildImage'/> it would be
+   <varname>redis/latest</varname>.
+  </para>
+
+  <para>
+   It is possible to inspect the arguments with which an image was built using
+   its <varname>buildArgs</varname> attribute.
+  </para>
+
+  <note>
+   <para>
+    If you see errors similar to <literal>getProtocolByName: does not exist (no
+    such protocol name: tcp)</literal> you may need to add
+    <literal>pkgs.iana-etc</literal> to <varname>contents</varname>.
+   </para>
+  </note>
+
+  <note>
+   <para>
+    If you see errors similar to <literal>Error_Protocol ("certificate has
+    unknown CA",True,UnknownCa)</literal> you may need to add
+    <literal>pkgs.cacert</literal> to <varname>contents</varname>.
+   </para>
+  </note>
+
+  <example xml:id="example-pkgs-dockerTools-buildImage-creation-date">
+   <title>Impurely Defining a Docker Layer's Creation Date</title>
+   <para>
+    By default <function>buildImage</function> will use a static date of one
+    second past the UNIX Epoch. This allows <function>buildImage</function> to
+    produce binary reproducible images. When listing images with
+    <command>docker list images</command>, the newly created images will be
+    listed like this:
+   </para>
+<screen><![CDATA[
+$ docker image list
+REPOSITORY   TAG      IMAGE ID       CREATED        SIZE
+hello        latest   08c791c7846e   48 years ago   25.2MB
+]]></screen>
+   <para>
+    You can break binary reproducibility but have a sorted, meaningful
+    <literal>CREATED</literal> column by setting <literal>created</literal> to
+    <literal>now</literal>.
+   </para>
+<programlisting><![CDATA[
+pkgs.dockerTools.buildImage {
+  name = "hello";
+  tag = "latest";
+  created = "now";
+  contents = pkgs.hello;
+
+  config.Cmd = [ "/bin/hello" ];
+}
+]]></programlisting>
+   <para>
+    and now the Docker CLI will display a reasonable date and sort the images
+    as expected:
+<screen><![CDATA[
+$ docker image list
+REPOSITORY   TAG      IMAGE ID       CREATED              SIZE
+hello        latest   de2bf4786de6   About a minute ago   25.2MB
+]]></screen>
+    however, the produced images will not be binary reproducible.
+   </para>
+  </example>
+ </section>
+
+ <section xml:id="ssec-pkgs-dockerTools-buildLayeredImage">
+  <title>buildLayeredImage</title>
+
+  <para>
+   Create a Docker image with many of the store paths being on their own layer
+   to improve sharing between images.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>name</varname>
+    </term>
+    <listitem>
+     <para>
+      The name of the resulting image.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>tag</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Tag of the generated image.
+     </para>
+     <para>
+      <emphasis>Default:</emphasis> the output path's hash
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>contents</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Top level paths in the container. Either a single derivation, or a list
+      of derivations.
+     </para>
+     <para>
+      <emphasis>Default:</emphasis> <literal>[]</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>config</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Run-time configuration of the container. A full list of the options are
+      available at in the
+      <link xlink:href="https://github.com/moby/moby/blob/master/image/spec/v1.2.md#image-json-field-descriptions">
+      Docker Image Specification v1.2.0 </link>.
+     </para>
+     <para>
+      <emphasis>Default:</emphasis> <literal>{}</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>created</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Date and time the layers were created. Follows the same
+      <literal>now</literal> exception supported by
+      <literal>buildImage</literal>.
+     </para>
+     <para>
+      <emphasis>Default:</emphasis> <literal>1970-01-01T00:00:01Z</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>maxLayers</varname> <emphasis>optional</emphasis>
+    </term>
+    <listitem>
+     <para>
+      Maximum number of layers to create.
+     </para>
+     <para>
+      <emphasis>Default:</emphasis> <literal>24</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <section xml:id="dockerTools-buildLayeredImage-arg-contents">
+   <title>Behavior of <varname>contents</varname> in the final image</title>
+
+   <para>
+    Each path directly listed in <varname>contents</varname> will have a
+    symlink in the root of the image.
+   </para>
+
+   <para>
+    For example:
+<programlisting><![CDATA[
+pkgs.dockerTools.buildLayeredImage {
+  name = "hello";
+  contents = [ pkgs.hello ];
+}
+]]></programlisting>
+    will create symlinks for all the paths in the <literal>hello</literal>
+    package:
+<screen><![CDATA[
+/bin/hello -> /nix/store/h1zb1padqbbb7jicsvkmrym3r6snphxg-hello-2.10/bin/hello
+/share/info/hello.info -> /nix/store/h1zb1padqbbb7jicsvkmrym3r6snphxg-hello-2.10/share/info/hello.info
+/share/locale/bg/LC_MESSAGES/hello.mo -> /nix/store/h1zb1padqbbb7jicsvkmrym3r6snphxg-hello-2.10/share/locale/bg/LC_MESSAGES/hello.mo
+]]></screen>
+   </para>
+  </section>
+
+  <section xml:id="dockerTools-buildLayeredImage-arg-config">
+   <title>Automatic inclusion of <varname>config</varname> references</title>
+
+   <para>
+    The closure of <varname>config</varname> is automatically included in the
+    closure of the final image.
+   </para>
+
+   <para>
+    This allows you to make very simple Docker images with very little code.
+    This container will start up and run <command>hello</command>:
+<programlisting><![CDATA[
+pkgs.dockerTools.buildLayeredImage {
+  name = "hello";
+  config.Cmd = [ "${pkgs.hello}/bin/hello" ];
+}
+]]></programlisting>
+   </para>
+  </section>
+
+  <section xml:id="dockerTools-buildLayeredImage-arg-maxLayers">
+   <title>Adjusting <varname>maxLayers</varname></title>
+
+   <para>
+    Increasing the <varname>maxLayers</varname> increases the number of layers
+    which have a chance to be shared between different images.
+   </para>
+
+   <para>
+    Modern Docker installations support up to 128 layers, however older
+    versions support as few as 42.
+   </para>
+
+   <para>
+    If the produced image will not be extended by other Docker builds, it is
+    safe to set <varname>maxLayers</varname> to <literal>128</literal>. However
+    it will be impossible to extend the image further.
+   </para>
+
+   <para>
+    The first (<literal>maxLayers-2</literal>) most "popular" paths will have
+    their own individual layers, then layer #<literal>maxLayers-1</literal>
+    will contain all the remaining "unpopular" paths, and finally layer
+    #<literal>maxLayers</literal> will contain the Image configuration.
+   </para>
+
+   <para>
+    Docker's Layers are not inherently ordered, they are content-addressable
+    and are not explicitly layered until they are composed in to an Image.
+   </para>
+  </section>
+ </section>
+
+ <section xml:id="ssec-pkgs-dockerTools-fetchFromRegistry">
+  <title>pullImage</title>
+
+  <para>
+   This function is analogous to the <command>docker pull</command> command, in
+   that can be used to pull a Docker image from a Docker registry. By default
+   <link xlink:href="https://hub.docker.com/">Docker Hub</link> is used to pull
+   images.
+  </para>
+
+  <para>
+   Its parameters are described in the example below:
+  </para>
+
+  <example xml:id='ex-dockerTools-pullImage'>
+   <title>Docker pull</title>
+<programlisting>
+pullImage {
+  imageName = "nixos/nix"; <co xml:id='ex-dockerTools-pullImage-1' />
+  imageDigest = "sha256:20d9485b25ecfd89204e843a962c1bd70e9cc6858d65d7f5fadc340246e2116b"; <co xml:id='ex-dockerTools-pullImage-2' />
+  finalImageTag = "1.11";  <co xml:id='ex-dockerTools-pullImage-3' />
+  sha256 = "0mqjy3zq2v6rrhizgb9nvhczl87lcfphq9601wcprdika2jz7qh8"; <co xml:id='ex-dockerTools-pullImage-4' />
+  os = "linux"; <co xml:id='ex-dockerTools-pullImage-5' />
+  arch = "x86_64"; <co xml:id='ex-dockerTools-pullImage-6' />
+}
+</programlisting>
+  </example>
+
+  <calloutlist>
+   <callout arearefs='ex-dockerTools-pullImage-1'>
+    <para>
+     <varname>imageName</varname> specifies the name of the image to be
+     downloaded, which can also include the registry namespace (e.g.
+     <literal>nixos</literal>). This argument is required.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-2'>
+    <para>
+     <varname>imageDigest</varname> specifies the digest of the image to be
+     downloaded. Skopeo can be used to get the digest of an image, with its
+     <varname>inspect</varname> subcommand. Since a given
+     <varname>imageName</varname> may transparently refer to a manifest list of
+     images which support multiple architectures and/or operating systems,
+     supply the `--override-os` and `--override-arch` arguments to specify
+     exactly which image you want. By default it will match the OS and
+     architecture of the host the command is run on.
+<programlisting>
+$ nix-shell --packages skopeo jq --command "skopeo --override-os linux --override-arch x86_64 inspect docker://docker.io/nixos/nix:1.11 | jq -r '.Digest'"
+sha256:20d9485b25ecfd89204e843a962c1bd70e9cc6858d65d7f5fadc340246e2116b
+</programlisting>
+     This argument is required.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-3'>
+    <para>
+     <varname>finalImageTag</varname>, if specified, this is the tag of the
+     image to be created. Note it is never used to fetch the image since we
+     prefer to rely on the immutable digest ID. By default it's
+     <literal>latest</literal>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-4'>
+    <para>
+     <varname>sha256</varname> is the checksum of the whole fetched image. This
+     argument is required.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-5'>
+    <para>
+     <varname>os</varname>, if specified, is the operating system of the
+     fetched image. By default it's <literal>linux</literal>.
+    </para>
+   </callout>
+   <callout arearefs='ex-dockerTools-pullImage-6'>
+    <para>
+     <varname>arch</varname>, if specified, is the cpu architecture of the
+     fetched image. By default it's <literal>x86_64</literal>.
+    </para>
+   </callout>
+  </calloutlist>
+ </section>
+
+ <section xml:id="ssec-pkgs-dockerTools-exportImage">
+  <title>exportImage</title>
+
+  <para>
+   This function is analogous to the <command>docker export</command> command,
+   in that can used to flatten a Docker image that contains multiple layers. It
+   is in fact the result of the merge of all the layers of the image. As such,
+   the result is suitable for being imported in Docker with <command>docker
+   import</command>.
+  </para>
+
+  <note>
+   <para>
+    Using this function requires the <literal>kvm</literal> device to be
+    available.
+   </para>
+  </note>
+
+  <para>
+   The parameters of <varname>exportImage</varname> are the following:
+  </para>
+
+  <example xml:id='ex-dockerTools-exportImage'>
+   <title>Docker export</title>
+<programlisting>
+exportImage {
+  fromImage = someLayeredImage;
+  fromImageName = null;
+  fromImageTag = null;
+
+  name = someLayeredImage.name;
+}
+  </programlisting>
+  </example>
+
+  <para>
+   The parameters relative to the base image have the same synopsis as
+   described in <xref linkend='ssec-pkgs-dockerTools-buildImage'/>, except that
+   <varname>fromImage</varname> is the only required argument in this case.
+  </para>
+
+  <para>
+   The <varname>name</varname> argument is the name of the derivation output,
+   which defaults to <varname>fromImage.name</varname>.
+  </para>
+ </section>
+
+ <section xml:id="ssec-pkgs-dockerTools-shadowSetup">
+  <title>shadowSetup</title>
+
+  <para>
+   This constant string is a helper for setting up the base files for managing
+   users and groups, only if such files don't exist already. It is suitable for
+   being used in a <varname>runAsRoot</varname>
+   <xref linkend='ex-dockerTools-buildImage-runAsRoot'/> script for cases like
+   in the example below:
+  </para>
+
+  <example xml:id='ex-dockerTools-shadowSetup'>
+   <title>Shadow base files</title>
+<programlisting>
+buildImage {
+  name = "shadow-basic";
+
+  runAsRoot = ''
+    #!${stdenv.shell}
+    ${shadowSetup}
+    groupadd -r redis
+    useradd -r -g redis redis
+    mkdir /data
+    chown redis:redis /data
+  '';
+}
+</programlisting>
+  </example>
+
+  <para>
+   Creating base files like <literal>/etc/passwd</literal> or
+   <literal>/etc/login.defs</literal> are necessary for shadow-utils to
+   manipulate users and groups.
+  </para>
+ </section>
+</section>
diff --git a/nixpkgs/doc/functions/fhs-environments.xml b/nixpkgs/doc/functions/fhs-environments.xml
new file mode 100644
index 000000000000..79682080be31
--- /dev/null
+++ b/nixpkgs/doc/functions/fhs-environments.xml
@@ -0,0 +1,142 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-fhs-environments">
+ <title>buildFHSUserEnv</title>
+
+ <para>
+  <function>buildFHSUserEnv</function> provides a way to build and run
+  FHS-compatible lightweight sandboxes. It creates an isolated root with bound
+  <filename>/nix/store</filename>, so its footprint in terms of disk space
+  needed is quite small. This allows one to run software which is hard or
+  unfeasible to patch for NixOS -- 3rd-party source trees with FHS assumptions,
+  games distributed as tarballs, software with integrity checking and/or
+  external self-updated binaries. It uses Linux namespaces feature to create
+  temporary lightweight environments which are destroyed after all child
+  processes exit, without root user rights requirement. Accepted arguments are:
+ </para>
+
+ <variablelist>
+  <varlistentry>
+   <term>
+    <literal>name</literal>
+   </term>
+   <listitem>
+    <para>
+     Environment name.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>targetPkgs</literal>
+   </term>
+   <listitem>
+    <para>
+     Packages to be installed for the main host's architecture (i.e. x86_64 on
+     x86_64 installations). Along with libraries binaries are also installed.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>multiPkgs</literal>
+   </term>
+   <listitem>
+    <para>
+     Packages to be installed for all architectures supported by a host (i.e.
+     i686 and x86_64 on x86_64 installations). Only libraries are installed by
+     default.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>extraBuildCommands</literal>
+   </term>
+   <listitem>
+    <para>
+     Additional commands to be executed for finalizing the directory structure.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>extraBuildCommandsMulti</literal>
+   </term>
+   <listitem>
+    <para>
+     Like <literal>extraBuildCommands</literal>, but executed only on multilib
+     architectures.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>extraOutputsToInstall</literal>
+   </term>
+   <listitem>
+    <para>
+     Additional derivation outputs to be linked for both target and
+     multi-architecture packages.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>extraInstallCommands</literal>
+   </term>
+   <listitem>
+    <para>
+     Additional commands to be executed for finalizing the derivation with
+     runner script.
+    </para>
+   </listitem>
+  </varlistentry>
+  <varlistentry>
+   <term>
+    <literal>runScript</literal>
+   </term>
+   <listitem>
+    <para>
+     A command that would be executed inside the sandbox and passed all the
+     command line arguments. It defaults to <literal>bash</literal>.
+    </para>
+   </listitem>
+  </varlistentry>
+ </variablelist>
+
+ <para>
+  One can create a simple environment using a <literal>shell.nix</literal> like
+  that:
+ </para>
+
+<programlisting><![CDATA[
+{ pkgs ? import <nixpkgs> {} }:
+
+(pkgs.buildFHSUserEnv {
+  name = "simple-x11-env";
+  targetPkgs = pkgs: (with pkgs;
+    [ udev
+      alsaLib
+    ]) ++ (with pkgs.xorg;
+    [ libX11
+      libXcursor
+      libXrandr
+    ]);
+  multiPkgs = pkgs: (with pkgs;
+    [ udev
+      alsaLib
+    ]);
+  runScript = "bash";
+}).env
+]]></programlisting>
+
+ <para>
+  Running <literal>nix-shell</literal> would then drop you into a shell with
+  these libraries and binaries available. You can use this to run closed-source
+  applications which expect FHS structure without hassles: simply change
+  <literal>runScript</literal> to the application path, e.g.
+  <filename>./bin/start.sh</filename> -- relative paths are supported.
+ </para>
+</section>
diff --git a/nixpkgs/doc/functions/generators.xml b/nixpkgs/doc/functions/generators.xml
new file mode 100644
index 000000000000..e860b10e8979
--- /dev/null
+++ b/nixpkgs/doc/functions/generators.xml
@@ -0,0 +1,89 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-generators">
+ <title>Generators</title>
+
+ <para>
+  Generators are functions that create file formats from nix data structures,
+  e. g. for configuration files. There are generators available for:
+  <literal>INI</literal>, <literal>JSON</literal> and <literal>YAML</literal>
+ </para>
+
+ <para>
+  All generators follow a similar call interface: <code>generatorName
+  configFunctions data</code>, where <literal>configFunctions</literal> is an
+  attrset of user-defined functions that format nested parts of the content.
+  They each have common defaults, so often they do not need to be set manually.
+  An example is <code>mkSectionName ? (name: libStr.escape [ "[" "]" ]
+  name)</code> from the <literal>INI</literal> generator. It receives the name
+  of a section and sanitizes it. The default <literal>mkSectionName</literal>
+  escapes <literal>[</literal> and <literal>]</literal> with a backslash.
+ </para>
+
+ <para>
+  Generators can be fine-tuned to produce exactly the file format required by
+  your application/service. One example is an INI-file format which uses
+  <literal>: </literal> as separator, the strings
+  <literal>"yes"</literal>/<literal>"no"</literal> as boolean values and
+  requires all string values to be quoted:
+ </para>
+
+<programlisting>
+with lib;
+let
+  customToINI = generators.toINI {
+    # specifies how to format a key/value pair
+    mkKeyValue = generators.mkKeyValueDefault {
+      # specifies the generated string for a subset of nix values
+      mkValueString = v:
+             if v == true then ''"yes"''
+        else if v == false then ''"no"''
+        else if isString v then ''"${v}"''
+        # and delegats all other values to the default generator
+        else generators.mkValueStringDefault {} v;
+    } ":";
+  };
+
+# the INI file can now be given as plain old nix values
+in customToINI {
+  main = {
+    pushinfo = true;
+    autopush = false;
+    host = "localhost";
+    port = 42;
+  };
+  mergetool = {
+    merge = "diff3";
+  };
+}
+</programlisting>
+
+ <para>
+  This will produce the following INI file as nix string:
+ </para>
+
+<programlisting>
+[main]
+autopush:"no"
+host:"localhost"
+port:42
+pushinfo:"yes"
+str\:ange:"very::strange"
+
+[mergetool]
+merge:"diff3"
+</programlisting>
+
+ <note>
+  <para>
+   Nix store paths can be converted to strings by enclosing a derivation
+   attribute like so: <code>"${drv}"</code>.
+  </para>
+ </note>
+
+ <para>
+  Detailed documentation for each generator can be found in
+  <literal>lib/generators.nix</literal>.
+ </para>
+</section>
diff --git a/nixpkgs/doc/functions/library.xml b/nixpkgs/doc/functions/library.xml
new file mode 100644
index 000000000000..901423c52a18
--- /dev/null
+++ b/nixpkgs/doc/functions/library.xml
@@ -0,0 +1,15 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-functions-library">
+ <title>Nixpkgs Library Functions</title>
+
+ <para>
+  Nixpkgs provides a standard library at <varname>pkgs.lib</varname>, or
+  through <code>import &lt;nixpkgs/lib&gt;</code>.
+ </para>
+
+ <xi:include href="./library/asserts.xml" />
+
+ <xi:include href="./library/attrsets.xml" />
+</section>
diff --git a/nixpkgs/doc/functions/library/asserts.xml b/nixpkgs/doc/functions/library/asserts.xml
new file mode 100644
index 000000000000..437850e408bc
--- /dev/null
+++ b/nixpkgs/doc/functions/library/asserts.xml
@@ -0,0 +1,117 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-functions-library-asserts">
+ <title>Assert functions</title>
+
+ <section xml:id="function-library-lib.asserts.assertMsg">
+  <title><function>lib.asserts.assertMsg</function></title>
+
+  <subtitle><literal>assertMsg :: Bool -> String -> Bool</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.asserts.assertMsg" />
+
+  <para>
+   Print a trace message if <literal>pred</literal> is false.
+  </para>
+
+  <para>
+   Intended to be used to augment asserts with helpful error messages.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>pred</varname>
+    </term>
+    <listitem>
+     <para>
+      Condition under which the <varname>msg</varname> should
+      <emphasis>not</emphasis> be printed.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>msg</varname>
+    </term>
+    <listitem>
+     <para>
+      Message to print.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.asserts.assertMsg-example-false">
+   <title>Printing when the predicate is false</title>
+<programlisting><![CDATA[
+assert lib.asserts.assertMsg ("foo" == "bar") "foo is not bar, silly"
+stderr> trace: foo is not bar, silly
+stderr> assert failed
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.asserts.assertOneOf">
+  <title><function>lib.asserts.assertOneOf</function></title>
+
+  <subtitle><literal>assertOneOf :: String -> String ->
+      StringList -> Bool</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.asserts.assertOneOf" />
+
+  <para>
+   Specialized <function>asserts.assertMsg</function> for checking if
+   <varname>val</varname> is one of the elements of <varname>xs</varname>.
+   Useful for checking enums.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>name</varname>
+    </term>
+    <listitem>
+     <para>
+      The name of the variable the user entered <varname>val</varname> into,
+      for inclusion in the error message.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>val</varname>
+    </term>
+    <listitem>
+     <para>
+      The value of what the user provided, to be compared against the values in
+      <varname>xs</varname>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>xs</varname>
+    </term>
+    <listitem>
+     <para>
+      The list of valid values.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.asserts.assertOneOf-example">
+   <title>Ensuring a user provided a possible value</title>
+<programlisting><![CDATA[
+let sslLibrary = "bearssl";
+in lib.asserts.assertOneOf "sslLibrary" sslLibrary [ "openssl" "bearssl" ];
+=> false
+stderr> trace: sslLibrary must be one of "openssl", "libressl", but is: "bearssl"
+        ]]></programlisting>
+  </example>
+ </section>
+</section>
diff --git a/nixpkgs/doc/functions/library/attrsets.xml b/nixpkgs/doc/functions/library/attrsets.xml
new file mode 100644
index 000000000000..65d0b40e2e82
--- /dev/null
+++ b/nixpkgs/doc/functions/library/attrsets.xml
@@ -0,0 +1,1731 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-functions-library-attrset">
+ <title>Attribute-Set Functions</title>
+
+ <section xml:id="function-library-lib.attrsets.attrByPath">
+  <title><function>lib.attrset.attrByPath</function></title>
+
+  <subtitle><literal>attrByPath :: [String] -> Any -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.attrByPath" />
+
+  <para>
+   Return an attribute from within nested attribute sets.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>attrPath</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of strings representing the path through the nested attribute set
+      <varname>set</varname>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>default</varname>
+    </term>
+    <listitem>
+     <para>
+      Default value if <varname>attrPath</varname> does not resolve to an
+      existing value.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>set</varname>
+    </term>
+    <listitem>
+     <para>
+      The nested attributeset to select values from.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrset.attrByPath-example-value-exists">
+   <title>Extracting a value from a nested attribute set</title>
+<programlisting><![CDATA[
+let set = { a = { b = 3; }; };
+in lib.attrsets.attrByPath [ "a" "b" ] 0 set
+=> 3
+]]></programlisting>
+  </example>
+
+  <example xml:id="function-library-lib.attrset.attrByPath-example-default-value">
+   <title>No value at the path, instead using the default</title>
+<programlisting><![CDATA[
+lib.attrsets.attrByPath [ "a" "b" ] 0 {}
+=> 0
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.hasAttrByPath">
+  <title><function>lib.attrsets.hasAttrByPath</function></title>
+
+  <subtitle><literal>hasAttrByPath :: [String] -> AttrSet -> Bool</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.hasAttrByPath" />
+
+  <para>
+   Determine if an attribute exists within a nested attribute set.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>attrPath</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of strings representing the path through the nested attribute set
+      <varname>set</varname>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>set</varname>
+    </term>
+    <listitem>
+     <para>
+      The nested attributeset to check.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.hasAttrByPath-example">
+   <title>A nested value does exist inside a set</title>
+<programlisting><![CDATA[
+lib.attrsets.hasAttrByPath
+  [ "a" "b" "c" "d" ]
+  { a = { b = { c = { d = 123; }; }; }; }
+=> true
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.setAttrByPath">
+  <title><function>lib.attrsets.setAttrByPath</function></title>
+
+  <subtitle><literal>setAttrByPath :: [String] -> Any -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.setAttrByPath" />
+
+  <para>
+   Create a new attribute set with <varname>value</varname> set at the nested
+   attribute location specified in <varname>attrPath</varname>.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>attrPath</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of strings representing the path through the nested attribute set.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>value</varname>
+    </term>
+    <listitem>
+     <para>
+      The value to set at the location described by
+      <varname>attrPath</varname>.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.setAttrByPath-example">
+   <title>Creating a new nested attribute set</title>
+<programlisting><![CDATA[
+lib.attrsets.setAttrByPath [ "a" "b" ] 3
+=> { a = { b = 3; }; }
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.getAttrFromPath">
+  <title><function>lib.attrsets.getAttrFromPath</function></title>
+
+  <subtitle><literal>getAttrFromPath :: [String] -> AttrSet -> Value</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.getAttrFromPath" />
+
+  <para>
+   Like <xref linkend="function-library-lib.attrsets.attrByPath" /> except
+   without a default, and it will throw if the value doesn't exist.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>attrPath</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of strings representing the path through the nested attribute set
+      <varname>set</varname>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>set</varname>
+    </term>
+    <listitem>
+     <para>
+      The nested attribute set to find the value in.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.getAttrPath-example-success">
+   <title>Succesfully getting a value from an attribute set</title>
+<programlisting><![CDATA[
+lib.attrsets.getAttrFromPath [ "a" "b" ] { a = { b = 3; }; }
+=> 3
+]]></programlisting>
+  </example>
+
+  <example xml:id="function-library-lib.attrsets.getAttrPath-example-throw">
+   <title>Throwing after failing to get a value from an attribute set</title>
+<programlisting><![CDATA[
+lib.attrsets.getAttrFromPath [ "x" "y" ] { }
+=> error: cannot find attribute `x.y'
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.attrVals">
+  <title><function>lib.attrsets.attrVals</function></title>
+
+  <subtitle><literal>attrVals :: [String] -> AttrSet -> [Any]</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.attrVals" />
+
+  <para>
+   Return the specified attributes from a set. All values must exist.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>nameList</varname>
+    </term>
+    <listitem>
+     <para>
+      The list of attributes to fetch from <varname>set</varname>. Each
+      attribute name must exist on the attrbitue set.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>set</varname>
+    </term>
+    <listitem>
+     <para>
+      The set to get attribute values from.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.attrVals-example-success">
+   <title>Getting several values from an attribute set</title>
+<programlisting><![CDATA[
+lib.attrsets.attrVals [ "a" "b" "c" ] { a = 1; b = 2; c = 3; }
+=> [ 1 2 3 ]
+]]></programlisting>
+  </example>
+
+  <example xml:id="function-library-lib.attrsets.attrVals-failure">
+   <title>Getting missing values from an attribute set</title>
+<programlisting><![CDATA[
+lib.attrsets.attrVals [ "d" ] { }
+error: attribute 'd' missing
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.attrValues">
+  <title><function>lib.attrsets.attrValues</function></title>
+
+  <subtitle><literal>attrValues :: AttrSet -> [Any]</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.attrValues" />
+
+  <para>
+   Get all the attribute values from an attribute set.
+  </para>
+
+  <para>
+   Provides a backwards-compatible interface of
+   <function>builtins.attrValues</function> for Nix version older than 1.8.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>attrs</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute set.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.attrValues-example">
+   <title></title>
+<programlisting><![CDATA[
+lib.attrsets.attrValues { a = 1; b = 2; c = 3; }
+=> [ 1 2 3 ]
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.catAttrs">
+  <title><function>lib.attrsets.catAttrs</function></title>
+
+  <subtitle><literal>catAttrs :: String -> AttrSet -> [Any]</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.catAttrs" />
+
+  <para>
+   Collect each attribute named `attr' from the list of attribute sets,
+   <varname>sets</varname>. Sets that don't contain the named attribute are
+   ignored.
+  </para>
+
+  <para>
+   Provides a backwards-compatible interface of
+   <function>builtins.catAttrs</function> for Nix version older than 1.9.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>attr</varname>
+    </term>
+    <listitem>
+     <para>
+      Attribute name to select from each attribute set in
+      <varname>sets</varname>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>sets</varname>
+    </term>
+    <listitem>
+     <para>
+      The list of attribute sets to select <varname>attr</varname> from.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.catAttrs-example">
+   <title>Collect an attribute from a list of attribute sets.</title>
+   <para>
+    Attribute sets which don't have the attribute are ignored.
+   </para>
+<programlisting><![CDATA[
+catAttrs "a" [{a = 1;} {b = 0;} {a = 2;}]
+=> [ 1 2 ]
+      ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.filterAttrs">
+  <title><function>lib.attrsets.filterAttrs</function></title>
+
+  <subtitle><literal>filterAttrs :: (String -> Any -> Bool) -> AttrSet -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.filterAttrs" />
+
+  <para>
+   Filter an attribute set by removing all attributes for which the given
+   predicate return false.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>pred</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>String -> Any -> Bool</literal>
+     </para>
+     <para>
+      Predicate which returns true to include an attribute, or returns false to
+      exclude it.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>name</varname>
+       </term>
+       <listitem>
+        <para>
+         The attribute's name
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>value</varname>
+       </term>
+       <listitem>
+        <para>
+         The attribute's value
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+     <para>
+      Returns <literal>true</literal> to include the attribute,
+      <literal>false</literal> to exclude the attribute.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>set</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute set to filter
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.filterAttrs-example">
+   <title>Filtering an attributeset</title>
+<programlisting><![CDATA[
+filterAttrs (n: v: n == "foo") { foo = 1; bar = 2; }
+=> { foo = 1; }
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.filterAttrsRecursive">
+  <title><function>lib.attrsets.filterAttrsRecursive</function></title>
+
+  <subtitle><literal>filterAttrsRecursive :: (String -> Any -> Bool) -> AttrSet -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.filterAttrsRecursive" />
+
+  <para>
+   Filter an attribute set recursively by removing all attributes for which the
+   given predicate return false.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>pred</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>String -> Any -> Bool</literal>
+     </para>
+     <para>
+      Predicate which returns true to include an attribute, or returns false to
+      exclude it.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>name</varname>
+       </term>
+       <listitem>
+        <para>
+         The attribute's name
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>value</varname>
+       </term>
+       <listitem>
+        <para>
+         The attribute's value
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+     <para>
+      Returns <literal>true</literal> to include the attribute,
+      <literal>false</literal> to exclude the attribute.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>set</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute set to filter
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.filterAttrsRecursive-example">
+   <title>Recursively filtering an attribute set</title>
+<programlisting><![CDATA[
+lib.attrsets.filterAttrsRecursive
+  (n: v: v != null)
+  {
+    levelA = {
+      example = "hi";
+      levelB = {
+        hello = "there";
+        this-one-is-present = {
+          this-is-excluded = null;
+        };
+      };
+      this-one-is-also-excluded = null;
+    };
+    also-excluded = null;
+  }
+=> {
+     levelA = {
+       example = "hi";
+       levelB = {
+         hello = "there";
+         this-one-is-present = { };
+       };
+     };
+   }
+     ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.foldAttrs">
+  <title><function>lib.attrsets.foldAttrs</function></title>
+
+  <subtitle><literal>foldAttrs :: (Any -> Any -> Any) -> Any -> [AttrSets] -> Any</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.foldAttrs" />
+
+  <para>
+   Apply fold function to values grouped by key.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>op</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>Any -> Any -> Any</literal>
+     </para>
+     <para>
+      Given a value <varname>val</varname> and a collector
+      <varname>col</varname>, combine the two.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>val</varname>
+       </term>
+       <listitem>
+        <para>
+         An attribute's value
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>col</varname>
+       </term>
+       <listitem>
+<!-- TODO: make this not bad, use more fold-ey terms -->
+        <para>
+         The result of previous <function>op</function> calls with other values
+         and <function>nul</function>.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>nul</varname>
+    </term>
+    <listitem>
+     <para>
+      The null-value, the starting value.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>list_of_attrs</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of attribute sets to fold together by key.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.foldAttrs-example">
+   <title>Combining an attribute of lists in to one attribute set</title>
+<programlisting><![CDATA[
+lib.attrsets.foldAttrs
+  (n: a: [n] ++ a) []
+  [
+    { a = 2; b = 7; }
+    { a = 3; }
+    { b = 6; }
+  ]
+=> { a = [ 2 3 ]; b = [ 7 6 ]; }
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.collect">
+  <title><function>lib.attrsets.collect</function></title>
+
+  <subtitle><literal>collect :: (Any -> Bool) -> AttrSet -> [Any]</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.collect" />
+
+  <para>
+   Recursively collect sets that verify a given predicate named
+   <varname>pred</varname> from the set <varname>attrs</varname>. The recursion
+   stops when <varname>pred</varname> returns <literal>true</literal>.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>pred</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>Any -> Bool</literal>
+     </para>
+     <para>
+      Given an attribute's value, determine if recursion should stop.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>value</varname>
+       </term>
+       <listitem>
+        <para>
+         The attribute set value.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>attrs</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute set to recursively collect.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.collect-example-lists">
+   <title>Collecting all lists from an attribute set</title>
+<programlisting><![CDATA[
+lib.attrsets.collect isList { a = { b = ["b"]; }; c = [1]; }
+=> [["b"] [1]]
+]]></programlisting>
+  </example>
+
+  <example xml:id="function-library-lib.attrsets.collect-example-outpath">
+   <title>Collecting all attribute-sets which contain the <literal>outPath</literal> attribute name.</title>
+<programlisting><![CDATA[
+collect (x: x ? outPath)
+  { a = { outPath = "a/"; }; b = { outPath = "b/"; }; }
+=> [{ outPath = "a/"; } { outPath = "b/"; }]
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.nameValuePair">
+  <title><function>lib.attrsets.nameValuePair</function></title>
+
+  <subtitle><literal>nameValuePair :: String -> Any -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.nameValuePair" />
+
+  <para>
+   Utility function that creates a <literal>{name, value}</literal> pair as
+   expected by <function>builtins.listToAttrs</function>.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>name</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute name.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>value</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute value.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.nameValuePair-example">
+   <title>Creating a name value pair</title>
+<programlisting><![CDATA[
+nameValuePair "some" 6
+=> { name = "some"; value = 6; }
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.mapAttrs">
+  <title><function>lib.attrsets.mapAttrs</function></title>
+
+  <subtitle><literal></literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.mapAttrs" />
+
+  <para>
+   Apply a function to each element in an attribute set, creating a new
+   attribute set.
+  </para>
+
+  <para>
+   Provides a backwards-compatible interface of
+   <function>builtins.mapAttrs</function> for Nix version older than 2.1.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>fn</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>String -> Any -> Any</literal>
+     </para>
+     <para>
+      Given an attribute's name and value, return a new value.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>name</varname>
+       </term>
+       <listitem>
+        <para>
+         The name of the attribute.
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>value</varname>
+       </term>
+       <listitem>
+        <para>
+         The attribute's value.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.mapAttrs-example">
+   <title>Modifying each value of an attribute set</title>
+<programlisting><![CDATA[
+lib.attrsets.mapAttrs
+  (name: value: name + "-" value)
+  { x = "foo"; y = "bar"; }
+=> { x = "x-foo"; y = "y-bar"; }
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.mapAttrs-prime">
+  <title><function>lib.attrsets.mapAttrs&apos;</function></title>
+
+  <subtitle><literal>mapAttrs' :: (String -> Any -> { name = String; value = Any }) -> AttrSet -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.mapAttrs-prime" />
+
+  <para>
+   Like <function>mapAttrs</function>, but allows the name of each attribute to
+   be changed in addition to the value. The applied function should return both
+   the new name and value as a <function>nameValuePair</function>.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>fn</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>String -> Any -> { name = String; value = Any }</literal>
+     </para>
+     <para>
+      Given an attribute's name and value, return a new
+      <link
+       linkend="function-library-lib.attrsets.nameValuePair">name
+      value pair</link>.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>name</varname>
+       </term>
+       <listitem>
+        <para>
+         The name of the attribute.
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>value</varname>
+       </term>
+       <listitem>
+        <para>
+         The attribute's value.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>set</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute set to map over.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.mapAttrs-prime-example">
+   <title>Change the name and value of each attribute of an attribute set</title>
+<programlisting><![CDATA[
+lib.attrsets.mapAttrs' (name: value: lib.attrsets.nameValuePair ("foo_" + name) ("bar-" + value))
+   { x = "a"; y = "b"; }
+=> { foo_x = "bar-a"; foo_y = "bar-b"; }
+
+    ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.mapAttrsToList">
+  <title><function>lib.attrsets.mapAttrsToList</function></title>
+
+  <subtitle><literal>mapAttrsToList :: (String -> Any -> Any) ->
+   AttrSet -> Any</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.mapAttrsToList" />
+
+  <para>
+   Call <varname>fn</varname> for each attribute in the given
+   <varname>set</varname> and return the result in a list.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>fn</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>String -> Any -> Any</literal>
+     </para>
+     <para>
+      Given an attribute's name and value, return a new value.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>name</varname>
+       </term>
+       <listitem>
+        <para>
+         The name of the attribute.
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>value</varname>
+       </term>
+       <listitem>
+        <para>
+         The attribute's value.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>set</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute set to map over.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.mapAttrsToList-example">
+   <title>Combine attribute values and names in to a list</title>
+<programlisting><![CDATA[
+lib.attrsets.mapAttrsToList (name: value: "${name}=${value}")
+   { x = "a"; y = "b"; }
+=> [ "x=a" "y=b" ]
+]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.mapAttrsRecursive">
+  <title><function>lib.attrsets.mapAttrsRecursive</function></title>
+
+  <subtitle><literal>mapAttrsRecursive :: ([String] > Any -> Any) -> AttrSet -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.mapAttrsRecursive" />
+
+  <para>
+   Like <function>mapAttrs</function>, except that it recursively applies
+   itself to attribute sets. Also, the first argument of the argument function
+   is a <emphasis>list</emphasis> of the names of the containing attributes.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>f</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>[ String ] -> Any -> Any</literal>
+     </para>
+     <para>
+      Given a list of attribute names and value, return a new value.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>name_path</varname>
+       </term>
+       <listitem>
+        <para>
+         The list of attribute names to this value.
+        </para>
+        <para>
+         For example, the <varname>name_path</varname> for the
+         <literal>example</literal> string in the attribute set <literal>{ foo
+         = { bar = "example"; }; }</literal> is <literal>[ "foo" "bar"
+         ]</literal>.
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>value</varname>
+       </term>
+       <listitem>
+        <para>
+         The attribute's value.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>set</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute set to recursively map over.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.mapAttrsRecursive-example">
+   <title>A contrived example of using <function>lib.attrsets.mapAttrsRecursive</function></title>
+<programlisting><![CDATA[
+mapAttrsRecursive
+  (path: value: concatStringsSep "-" (path ++ [value]))
+  {
+    n = {
+      a = "A";
+      m = {
+        b = "B";
+        c = "C";
+      };
+    };
+    d = "D";
+  }
+=> {
+     n = {
+       a = "n-a-A";
+       m = {
+         b = "n-m-b-B";
+         c = "n-m-c-C";
+       };
+     };
+     d = "d-D";
+   }
+    ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.mapAttrsRecursiveCond">
+  <title><function>lib.attrsets.mapAttrsRecursiveCond</function></title>
+
+  <subtitle><literal>mapAttrsRecursiveCond :: (AttrSet -> Bool) -> ([ String ] -> Any -> Any) -> AttrSet -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.mapAttrsRecursiveCond" />
+
+  <para>
+   Like <function>mapAttrsRecursive</function>, but it takes an additional
+   predicate function that tells it whether to recursive into an attribute set.
+   If it returns false, <function>mapAttrsRecursiveCond</function> does not
+   recurse, but does apply the map function. It is returns true, it does
+   recurse, and does not apply the map function.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>cond</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>(AttrSet -> Bool)</literal>
+     </para>
+     <para>
+      Determine if <function>mapAttrsRecursive</function> should recurse deeper
+      in to the attribute set.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>attributeset</varname>
+       </term>
+       <listitem>
+        <para>
+         An attribute set.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>f</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>[ String ] -> Any -> Any</literal>
+     </para>
+     <para>
+      Given a list of attribute names and value, return a new value.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>name_path</varname>
+       </term>
+       <listitem>
+        <para>
+         The list of attribute names to this value.
+        </para>
+        <para>
+         For example, the <varname>name_path</varname> for the
+         <literal>example</literal> string in the attribute set <literal>{ foo
+         = { bar = "example"; }; }</literal> is <literal>[ "foo" "bar"
+         ]</literal>.
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>value</varname>
+       </term>
+       <listitem>
+        <para>
+         The attribute's value.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>set</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute set to recursively map over.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.mapAttrsRecursiveCond-example">
+   <title>Only convert attribute values to JSON if the containing attribute set is marked for recursion</title>
+<programlisting><![CDATA[
+lib.attrsets.mapAttrsRecursiveCond
+  ({ recurse ? false, ... }: recurse)
+  (name: value: builtins.toJSON value)
+  {
+    dorecur = {
+      recurse = true;
+      hello = "there";
+    };
+    dontrecur = {
+      converted-to- = "json";
+    };
+  }
+=> {
+     dorecur = {
+       hello = "\"there\"";
+       recurse = "true";
+     };
+     dontrecur = "{\"converted-to\":\"json\"}";
+   }
+    ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.genAttrs">
+  <title><function>lib.attrsets.genAttrs</function></title>
+
+  <subtitle><literal>genAttrs :: [ String ] -> (String -> Any) -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.genAttrs" />
+
+  <para>
+   Generate an attribute set by mapping a function over a list of attribute
+   names.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>names</varname>
+    </term>
+    <listitem>
+     <para>
+      Names of values in the resulting attribute set.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>f</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>String -> Any</literal>
+     </para>
+     <para>
+      Takes the name of the attribute and return the attribute's value.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>name</varname>
+       </term>
+       <listitem>
+        <para>
+         The name of the attribute to generate a value for.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.genAttrs-example">
+   <title>Generate an attrset based on names only</title>
+<programlisting><![CDATA[
+lib.attrsets.genAttrs [ "foo" "bar" ] (name: "x_${name}")
+=> { foo = "x_foo"; bar = "x_bar"; }
+     ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.isDerivation">
+  <title><function>lib.attrsets.isDerivation</function></title>
+
+  <subtitle><literal>isDerivation :: Any -> Bool</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.isDerivation" />
+
+  <para>
+   Check whether the argument is a derivation. Any set with <code>{ type =
+   "derivation"; }</code> counts as a derivation.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>value</varname>
+    </term>
+    <listitem>
+     <para>
+      The value which is possibly a derivation.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.isDerivation-example-true">
+   <title>A package is a derivation</title>
+<programlisting><![CDATA[
+lib.attrsets.isDerivation (import <nixpkgs> {}).ruby
+=> true
+     ]]></programlisting>
+  </example>
+
+  <example xml:id="function-library-lib.attrsets.isDerivation-example-false">
+   <title>Anything else is not a derivation</title>
+<programlisting><![CDATA[
+lib.attrsets.isDerivation "foobar"
+=> false
+     ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.toDerivation">
+  <title><function>lib.attrsets.toDerivation</function></title>
+
+  <subtitle><literal>toDerivation :: Path -> Derivation</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.toDerivation" />
+
+  <para>
+   Converts a store path to a fake derivation.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>path</varname>
+    </term>
+    <listitem>
+     <para>
+      A store path to convert to a derivation.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.optionalAttrs">
+  <title><function>lib.attrsets.optionalAttrs</function></title>
+
+  <subtitle><literal>optionalAttrs :: Bool -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.optionalAttrs" />
+
+  <para>
+   Conditionally return an attribute set or an empty attribute set.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>cond</varname>
+    </term>
+    <listitem>
+     <para>
+      Condition under which the <varname>as</varname> attribute set is
+      returned.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>as</varname>
+    </term>
+    <listitem>
+     <para>
+      The attribute set to return if <varname>cond</varname> is true.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.optionalAttrs-example-true">
+   <title>Return the provided attribute set when <varname>cond</varname> is true</title>
+<programlisting><![CDATA[
+lib.attrsets.optionalAttrs true { my = "set"; }
+=> { my = "set"; }
+     ]]></programlisting>
+  </example>
+
+  <example xml:id="function-library-lib.attrsets.optionalAttrs-example-false">
+   <title>Return an empty attribute set when <varname>cond</varname> is false</title>
+<programlisting><![CDATA[
+lib.attrsets.optionalAttrs false { my = "set"; }
+=> { }
+     ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.zipAttrsWithNames">
+  <title><function>lib.attrsets.zipAttrsWithNames</function></title>
+
+  <subtitle><literal>zipAttrsWithNames :: [ String ] -> (String -> [ Any ] -> Any) -> [ AttrSet ] -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.zipAttrsWithNames" />
+
+  <para>
+   Merge sets of attributes and use the function <varname>f</varname> to merge
+   attribute values where the attribute name is in <varname>names</varname>.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>names</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of attribute names to zip.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>f</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>(String -> [ Any ] -> Any</literal>
+     </para>
+     <para>
+      Accepts an attribute name, all the values, and returns a combined value.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>name</varname>
+       </term>
+       <listitem>
+        <para>
+         The name of the attribute each value came from.
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>vs</varname>
+       </term>
+       <listitem>
+        <para>
+         A list of values collected from the list of attribute sets.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>sets</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of attribute sets to zip together.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.zipAttrsWithNames-example">
+   <title>Summing a list of attribute sets of numbers</title>
+<programlisting><![CDATA[
+lib.attrsets.zipAttrsWithNames
+  [ "a" "b" ]
+  (name: vals: "${name} ${toString (builtins.foldl' (a: b: a + b) 0 vals)}")
+  [
+    { a = 1; b = 1; c = 1; }
+    { a = 10; }
+    { b = 100; }
+    { c = 1000; }
+  ]
+=> { a = "a 11"; b = "b 101"; }
+     ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.zipAttrsWith">
+  <title><function>lib.attrsets.zipAttrsWith</function></title>
+
+  <subtitle><literal>zipAttrsWith :: (String -> [ Any ] -> Any) -> [ AttrSet ] -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.zipAttrsWith" />
+
+  <para>
+   Merge sets of attributes and use the function <varname>f</varname> to merge
+   attribute values. Similar to
+   <xref
+   linkend="function-library-lib.attrsets.zipAttrsWithNames" /> where
+   all key names are passed for <varname>names</varname>.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>f</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>(String -> [ Any ] -> Any</literal>
+     </para>
+     <para>
+      Accepts an attribute name, all the values, and returns a combined value.
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>name</varname>
+       </term>
+       <listitem>
+        <para>
+         The name of the attribute each value came from.
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>vs</varname>
+       </term>
+       <listitem>
+        <para>
+         A list of values collected from the list of attribute sets.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>sets</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of attribute sets to zip together.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.zipAttrsWith-example">
+   <title>Summing a list of attribute sets of numbers</title>
+<programlisting><![CDATA[
+lib.attrsets.zipAttrsWith
+  (name: vals: "${name} ${toString (builtins.foldl' (a: b: a + b) 0 vals)}")
+  [
+    { a = 1; b = 1; c = 1; }
+    { a = 10; }
+    { b = 100; }
+    { c = 1000; }
+  ]
+=> { a = "a 11"; b = "b 101"; c = "c 1001"; }
+     ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.zipAttrs">
+  <title><function>lib.attrsets.zipAttrs</function></title>
+
+  <subtitle><literal>zipAttrsWith :: [ AttrSet ] -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.zipAttrs" />
+
+  <para>
+   Merge sets of attributes and combine each attribute value in to a list.
+   Similar to <xref linkend="function-library-lib.attrsets.zipAttrsWith" />
+   where the merge function returns a list of all values.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>sets</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of attribute sets to zip together.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.zipAttrs-example">
+   <title>Combining a list of attribute sets</title>
+<programlisting><![CDATA[
+lib.attrsets.zipAttrs
+  [
+    { a = 1; b = 1; c = 1; }
+    { a = 10; }
+    { b = 100; }
+    { c = 1000; }
+  ]
+=> { a = [ 1 10 ]; b = [ 1 100 ]; c = [ 1 1000 ]; }
+     ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.recursiveUpdateUntil">
+  <title><function>lib.attrsets.recursiveUpdateUntil</function></title>
+
+  <subtitle><literal>recursiveUpdateUntil :: ( [ String ] -> AttrSet -> AttrSet -> Bool ) -> AttrSet -> AttrSet -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.recursiveUpdateUntil" />
+
+  <para>
+   Does the same as the update operator <literal>//</literal> except that
+   attributes are merged until the given predicate is verified. The predicate
+   should accept 3 arguments which are the path to reach the attribute, a part
+   of the first attribute set and a part of the second attribute set. When the
+   predicate is verified, the value of the first attribute set is replaced by
+   the value of the second attribute set.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>pred</varname>
+    </term>
+    <listitem>
+     <para>
+      <literal>[ String ] -> AttrSet -> AttrSet -> Bool</literal>
+     </para>
+     <variablelist>
+      <varlistentry>
+       <term>
+        <varname>path</varname>
+       </term>
+       <listitem>
+        <para>
+         The path to the values in the left and right hand sides.
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>l</varname>
+       </term>
+       <listitem>
+        <para>
+         The left hand side value.
+        </para>
+       </listitem>
+      </varlistentry>
+      <varlistentry>
+       <term>
+        <varname>r</varname>
+       </term>
+       <listitem>
+        <para>
+         The right hand side value.
+        </para>
+       </listitem>
+      </varlistentry>
+     </variablelist>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>lhs</varname>
+    </term>
+    <listitem>
+     <para>
+      The left hand attribute set of the merge.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>rhs</varname>
+    </term>
+    <listitem>
+     <para>
+      The right hand attribute set of the merge.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.recursiveUpdateUntil-example">
+   <title>Recursively merging two attribute sets</title>
+<programlisting><![CDATA[
+lib.attrsets.recursiveUpdateUntil (path: l: r: path == ["foo"])
+  {
+    # first attribute set
+    foo.bar = 1;
+    foo.baz = 2;
+    bar = 3;
+  }
+  {
+    #second attribute set
+    foo.bar = 1;
+    foo.quz = 2;
+    baz = 4;
+  }
+=> {
+  foo.bar = 1; # 'foo.*' from the second set
+  foo.quz = 2; #
+  bar = 3;     # 'bar' from the first set
+  baz = 4;     # 'baz' from the second set
+}
+     ]]></programlisting>
+  </example>
+ </section>
+
+ <section xml:id="function-library-lib.attrsets.recursiveUpdate">
+  <title><function>lib.attrsets.recursiveUpdate</function></title>
+
+  <subtitle><literal>recursiveUpdate :: AttrSet -> AttrSet -> AttrSet</literal>
+  </subtitle>
+
+  <xi:include href="./locations.xml" xpointer="lib.attrsets.recursiveUpdate" />
+
+  <para>
+   A recursive variant of the update operator <literal>//</literal>. The
+   recursion stops when one of the attribute values is not an attribute set, in
+   which case the right hand side value takes precedence over the left hand
+   side value.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>lhs</varname>
+    </term>
+    <listitem>
+     <para>
+      The left hand attribute set of the merge.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>rhs</varname>
+    </term>
+    <listitem>
+     <para>
+      The right hand attribute set of the merge.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <example xml:id="function-library-lib.attrsets.recursiveUpdate-example">
+   <title>Recursively merging two attribute sets</title>
+<programlisting><![CDATA[
+recursiveUpdate
+  {
+    boot.loader.grub.enable = true;
+    boot.loader.grub.device = "/dev/hda";
+  }
+  {
+    boot.loader.grub.device = "";
+  }
+=> {
+  boot.loader.grub.enable = true;
+  boot.loader.grub.device = "";
+}
+]]></programlisting>
+  </example>
+ </section>
+</section>
diff --git a/nixpkgs/doc/functions/overrides.xml b/nixpkgs/doc/functions/overrides.xml
new file mode 100644
index 000000000000..1bd90d2a0c76
--- /dev/null
+++ b/nixpkgs/doc/functions/overrides.xml
@@ -0,0 +1,212 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-overrides">
+ <title>Overriding</title>
+
+ <para>
+  Sometimes one wants to override parts of <literal>nixpkgs</literal>, e.g.
+  derivation attributes, the results of derivations.
+ </para>
+
+ <para>
+  These functions are used to make changes to packages, returning only single
+  packages. <link xlink:href="#chap-overlays">Overlays</link>, on the other
+  hand, can be used to combine the overridden packages across the entire
+  package set of Nixpkgs.
+ </para>
+
+ <section xml:id="sec-pkg-override">
+  <title>&lt;pkg&gt;.override</title>
+
+  <para>
+   The function <varname>override</varname> is usually available for all the
+   derivations in the nixpkgs expression (<varname>pkgs</varname>).
+  </para>
+
+  <para>
+   It is used to override the arguments passed to a function.
+  </para>
+
+  <para>
+   Example usages:
+<programlisting>pkgs.foo.override { arg1 = val1; arg2 = val2; ... }</programlisting>
+<!-- TODO: move below programlisting to a new section about extending and overlays
+           and reference it
+  -->
+<programlisting>
+import pkgs.path { overlays = [ (self: super: {
+  foo = super.foo.override { barSupport = true ; };
+  })]};
+</programlisting>
+<programlisting>
+mypkg = pkgs.callPackage ./mypkg.nix {
+  mydep = pkgs.mydep.override { ... };
+  }
+</programlisting>
+  </para>
+
+  <para>
+   In the first example, <varname>pkgs.foo</varname> is the result of a
+   function call with some default arguments, usually a derivation. Using
+   <varname>pkgs.foo.override</varname> will call the same function with the
+   given new arguments.
+  </para>
+ </section>
+
+ <section xml:id="sec-pkg-overrideAttrs">
+  <title>&lt;pkg&gt;.overrideAttrs</title>
+
+  <para>
+   The function <varname>overrideAttrs</varname> allows overriding the
+   attribute set passed to a <varname>stdenv.mkDerivation</varname> call,
+   producing a new derivation based on the original one. This function is
+   available on all derivations produced by the
+   <varname>stdenv.mkDerivation</varname> function, which is most packages in
+   the nixpkgs expression <varname>pkgs</varname>.
+  </para>
+
+  <para>
+   Example usage:
+<programlisting>
+helloWithDebug = pkgs.hello.overrideAttrs (oldAttrs: rec {
+  separateDebugInfo = true;
+});
+</programlisting>
+  </para>
+
+  <para>
+   In the above example, the <varname>separateDebugInfo</varname> attribute is
+   overridden to be true, thus building debug info for
+   <varname>helloWithDebug</varname>, while all other attributes will be
+   retained from the original <varname>hello</varname> package.
+  </para>
+
+  <para>
+   The argument <varname>oldAttrs</varname> is conventionally used to refer to
+   the attr set originally passed to <varname>stdenv.mkDerivation</varname>.
+  </para>
+
+  <note>
+   <para>
+    Note that <varname>separateDebugInfo</varname> is processed only by the
+    <varname>stdenv.mkDerivation</varname> function, not the generated, raw Nix
+    derivation. Thus, using <varname>overrideDerivation</varname> will not work
+    in this case, as it overrides only the attributes of the final derivation.
+    It is for this reason that <varname>overrideAttrs</varname> should be
+    preferred in (almost) all cases to <varname>overrideDerivation</varname>,
+    i.e. to allow using <varname>stdenv.mkDerivation</varname> to process input
+    arguments, as well as the fact that it is easier to use (you can use the
+    same attribute names you see in your Nix code, instead of the ones
+    generated (e.g. <varname>buildInputs</varname> vs
+    <varname>nativeBuildInputs</varname>), and it involves less typing).
+   </para>
+  </note>
+ </section>
+
+ <section xml:id="sec-pkg-overrideDerivation">
+  <title>&lt;pkg&gt;.overrideDerivation</title>
+
+  <warning>
+   <para>
+    You should prefer <varname>overrideAttrs</varname> in almost all cases, see
+    its documentation for the reasons why.
+    <varname>overrideDerivation</varname> is not deprecated and will continue
+    to work, but is less nice to use and does not have as many abilities as
+    <varname>overrideAttrs</varname>.
+   </para>
+  </warning>
+
+  <warning>
+   <para>
+    Do not use this function in Nixpkgs as it evaluates a Derivation before
+    modifying it, which breaks package abstraction and removes error-checking
+    of function arguments. In addition, this evaluation-per-function
+    application incurs a performance penalty, which can become a problem if
+    many overrides are used. It is only intended for ad-hoc customisation, such
+    as in <filename>~/.config/nixpkgs/config.nix</filename>.
+   </para>
+  </warning>
+
+  <para>
+   The function <varname>overrideDerivation</varname> creates a new derivation
+   based on an existing one by overriding the original's attributes with the
+   attribute set produced by the specified function. This function is available
+   on all derivations defined using the <varname>makeOverridable</varname>
+   function. Most standard derivation-producing functions, such as
+   <varname>stdenv.mkDerivation</varname>, are defined using this function,
+   which means most packages in the nixpkgs expression,
+   <varname>pkgs</varname>, have this function.
+  </para>
+
+  <para>
+   Example usage:
+<programlisting>
+mySed = pkgs.gnused.overrideDerivation (oldAttrs: {
+  name = "sed-4.2.2-pre";
+  src = fetchurl {
+    url = ftp://alpha.gnu.org/gnu/sed/sed-4.2.2-pre.tar.bz2;
+    sha256 = "11nq06d131y4wmf3drm0yk502d2xc6n5qy82cg88rb9nqd2lj41k";
+  };
+  patches = [];
+});
+</programlisting>
+  </para>
+
+  <para>
+   In the above example, the <varname>name</varname>, <varname>src</varname>,
+   and <varname>patches</varname> of the derivation will be overridden, while
+   all other attributes will be retained from the original derivation.
+  </para>
+
+  <para>
+   The argument <varname>oldAttrs</varname> is used to refer to the attribute
+   set of the original derivation.
+  </para>
+
+  <note>
+   <para>
+    A package's attributes are evaluated *before* being modified by the
+    <varname>overrideDerivation</varname> function. For example, the
+    <varname>name</varname> attribute reference in <varname>url =
+    "mirror://gnu/hello/${name}.tar.gz";</varname> is filled-in *before* the
+    <varname>overrideDerivation</varname> function modifies the attribute set.
+    This means that overriding the <varname>name</varname> attribute, in this
+    example, *will not* change the value of the <varname>url</varname>
+    attribute. Instead, we need to override both the <varname>name</varname>
+    *and* <varname>url</varname> attributes.
+   </para>
+  </note>
+ </section>
+
+ <section xml:id="sec-lib-makeOverridable">
+  <title>lib.makeOverridable</title>
+
+  <para>
+   The function <varname>lib.makeOverridable</varname> is used to make the
+   result of a function easily customizable. This utility only makes sense for
+   functions that accept an argument set and return an attribute set.
+  </para>
+
+  <para>
+   Example usage:
+<programlisting>
+f = { a, b }: { result = a+b; };
+c = lib.makeOverridable f { a = 1; b = 2; };
+</programlisting>
+  </para>
+
+  <para>
+   The variable <varname>c</varname> is the value of the <varname>f</varname>
+   function applied with some default arguments. Hence the value of
+   <varname>c.result</varname> is <literal>3</literal>, in this example.
+  </para>
+
+  <para>
+   The variable <varname>c</varname> however also has some additional
+   functions, like <link linkend="sec-pkg-override">c.override</link> which can
+   be used to override the default arguments. In this example the value of
+   <varname>(c.override { a = 4; }).result</varname> is 6.
+  </para>
+ </section>
+</section>
diff --git a/nixpkgs/doc/functions/shell.xml b/nixpkgs/doc/functions/shell.xml
new file mode 100644
index 000000000000..e5031c9463c0
--- /dev/null
+++ b/nixpkgs/doc/functions/shell.xml
@@ -0,0 +1,26 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="sec-pkgs-mkShell">
+ <title>pkgs.mkShell</title>
+
+ <para>
+  <function>pkgs.mkShell</function> is a special kind of derivation that is
+  only useful when using it combined with <command>nix-shell</command>. It will
+  in fact fail to instantiate when invoked with <command>nix-build</command>.
+ </para>
+
+ <section xml:id="sec-pkgs-mkShell-usage">
+  <title>Usage</title>
+
+<programlisting><![CDATA[
+{ pkgs ? import <nixpkgs> {} }:
+pkgs.mkShell {
+  # this will make all the build inputs from hello and gnutar
+  # available to the shell environment
+  inputsFrom = with pkgs; [ hello gnutar ];
+  buildInputs = [ pkgs.gnumake ];
+}
+]]></programlisting>
+ </section>
+</section>
diff --git a/nixpkgs/doc/introduction.chapter.md b/nixpkgs/doc/introduction.chapter.md
new file mode 100644
index 000000000000..6abdc2714e2c
--- /dev/null
+++ b/nixpkgs/doc/introduction.chapter.md
@@ -0,0 +1,51 @@
+---
+title: Introduction
+author: Frederik Rietdijk
+date: 2015-11-25
+---
+
+# Introduction
+
+The Nix Packages collection (Nixpkgs) is a set of thousands of packages for the
+[Nix package manager](http://nixos.org/nix/), released under a
+[permissive MIT/X11 license](https://github.com/NixOS/nixpkgs/blob/master/COPYING).
+Packages are available for several platforms, and can be used with the Nix
+package manager on most GNU/Linux distributions as well as NixOS.
+
+This manual primarily describes how to write packages for the Nix Packages collection
+(Nixpkgs). Thus it’s mainly for packagers and developers who want to add packages to
+Nixpkgs. If you like to learn more about the Nix package manager and the Nix
+expression language, then you are kindly referred to the [Nix manual](http://nixos.org/nix/manual/).
+
+## Overview of Nixpkgs
+
+Nix expressions describe how to build packages from source and are collected in
+the [nixpkgs repository](https://github.com/NixOS/nixpkgs). Also included in the
+collection are Nix expressions for
+[NixOS modules](http://nixos.org/nixos/manual/index.html#sec-writing-modules).
+With these expressions the Nix package manager can build binary packages.
+
+Packages, including the Nix packages collection, are distributed through
+[channels](http://nixos.org/nix/manual/#sec-channels). The collection is
+distributed for users of Nix on non-NixOS distributions through the channel
+`nixpkgs`. Users of NixOS generally use one of the `nixos-*` channels, e.g.
+`nixos-16.03`, which includes all packages and modules for the stable NixOS
+16.03. Stable NixOS releases are generally only given
+security updates. More up to date packages and modules are available via the
+`nixos-unstable` channel.
+
+Both `nixos-unstable` and `nixpkgs` follow the `master` branch of the Nixpkgs
+repository, although both do lag the `master` branch by generally
+[a couple of days](http://howoldis.herokuapp.com/). Updates to a channel are
+distributed as soon as all tests for that channel pass, e.g.
+[this table](http://hydra.nixos.org/job/nixpkgs/trunk/unstable#tabs-constituents)
+shows the status of tests for the `nixpkgs` channel.
+
+The tests are conducted by a cluster called [Hydra](http://nixos.org/hydra/),
+which also builds binary packages from the Nix expressions in Nixpkgs for
+`x86_64-linux`, `i686-linux` and `x86_64-darwin`.
+The binaries are made available via a [binary cache](https://cache.nixos.org).
+
+The current Nix expressions of the channels are available in the
+[`nixpkgs-channels`](https://github.com/NixOS/nixpkgs-channels) repository,
+which has branches corresponding to the available channels.
diff --git a/nixpkgs/doc/languages-frameworks/android.section.md b/nixpkgs/doc/languages-frameworks/android.section.md
new file mode 100644
index 000000000000..237f3441874f
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/android.section.md
@@ -0,0 +1,240 @@
+---
+title: Android
+author: Sander van der Burg
+date: 2018-11-18
+---
+# Android
+
+The Android build environment provides three major features and a number of
+supporting features.
+
+Deploying an Android SDK installation with plugins
+--------------------------------------------------
+The first use case is deploying the SDK with a desired set of plugins or subsets
+of an SDK.
+
+```nix
+with import <nixpkgs> {};
+
+let
+  androidComposition = androidenv.composeAndroidPackages {
+    toolsVersion = "25.2.5";
+    platformToolsVersion = "27.0.1";
+    buildToolsVersions = [ "27.0.3" ];
+    includeEmulator = false;
+    emulatorVersion = "27.2.0";
+    platformVersions = [ "24" ];
+    includeSources = false;
+    includeDocs = false;
+    includeSystemImages = false;
+    systemImageTypes = [ "default" ];
+    abiVersions = [ "armeabi-v7a" ];
+    lldbVersions = [ "2.0.2558144" ];
+    cmakeVersions = [ "3.6.4111459" ];
+    includeNDK = false;
+    ndkVersion = "16.1.4479499";
+    useGoogleAPIs = false;
+    useGoogleTVAddOns = false;
+    includeExtras = [
+      "extras;google;gcm"
+    ];
+  };
+in
+androidComposition.androidsdk
+```
+
+The above function invocation states that we want an Android SDK with the above
+specified plugin versions. By default, most plugins are disabled. Notable
+exceptions are the tools, platform-tools and build-tools sub packages.
+
+The following parameters are supported:
+
+* `toolsVersion`, specifies the version of the tools package to use
+* `platformsToolsVersion` specifies the version of the `platform-tools` plugin
+* `buildToolsVersion` specifies the versions of the `build-tools` plugins to
+  use.
+* `includeEmulator` specifies whether to deploy the emulator package (`false`
+  by default). When enabled, the version of the emulator to deploy can be
+  specified by setting the `emulatorVersion` parameter.
+* `includeDocs` specifies whether the documentation catalog should be included.
+* `lldbVersions` specifies what LLDB versions should be deployed.
+* `cmakeVersions` specifies which CMake versions should be deployed.
+* `includeNDK` specifies that the Android NDK bundle should be included.
+  Defaults to: `false`.
+* `ndkVersion` specifies the NDK version that we want to use.
+* `includeExtras` is an array of identifier strings referring to arbitrary
+  add-on packages that should be installed.
+* `platformVersions` specifies which platform SDK versions should be included.
+
+For each platform version that has been specified, we can apply the following
+options:
+
+* `includeSystemImages` specifies whether a system image for each platform SDK
+  should be included.
+* `includeSources` specifies whether the sources for each SDK version should be
+  included.
+* `useGoogleAPIs` specifies that for each selected platform version the
+  Google API should be included.
+* `useGoogleTVAddOns` specifies that for each selected platform version the
+  Google TV add-on should be included.
+
+For each requested system image we can specify the following options:
+
+* `systemImageTypes` specifies what kind of system images should be included.
+  Defaults to: `default`.
+* `abiVersions` specifies what kind of ABI version of each system image should
+  be included. Defaults to: `armeabi-v7a`.
+
+Most of the function arguments have reasonable default settings.
+
+When building the above expression with:
+
+```bash
+$ nix-build
+```
+
+The Android SDK gets deployed with all desired plugin versions.
+
+We can also deploy subsets of the Android SDK. For example, to only the the
+`platform-tools` package, you can evaluate the following expression:
+
+```nix
+with import <nixpkgs> {};
+
+let
+  androidComposition = androidenv.composeAndroidPackages {
+    # ...
+  };
+in
+androidComposition.platform-tools
+```
+
+Using predefine Android package compositions
+--------------------------------------------
+In addition to composing an Android package set manually, it is also possible
+to use a predefined composition that contains all basic packages for a specific
+Android version, such as version 9.0 (API-level 28).
+
+The following Nix expression can be used to deploy the entire SDK with all basic
+plugins:
+
+```nix
+with import <nixpkgs> {};
+
+androidenv.androidPkgs_9_0.androidsdk
+```
+
+It is also possible to use one plugin only:
+
+```nix
+with import <nixpkgs> {};
+
+androidenv.androidPkgs_9_0.platform-tools
+```
+
+Building an Android application
+-------------------------------
+In addition to the SDK, it is also possible to build an Ant-based Android
+project and automatically deploy all the Android plugins that a project
+requires.
+
+```nix
+with import <nixpkgs> {};
+
+androidenv.buildApp {
+  name = "MyAndroidApp";
+  src = ./myappsources;
+  release = true;
+
+  # If release is set to true, you need to specify the following parameters
+  keyStore = ./keystore;
+  keyAlias = "myfirstapp";
+  keyStorePassword = "mykeystore";
+  keyAliasPassword = "myfirstapp";
+
+  # Any Android SDK parameters that install all the relevant plugins that a
+  # build requires
+  platformVersions = [ "24" ];
+
+  # When we include the NDK, then ndk-build is invoked before Ant gets invoked
+  includeNDK = true;
+}
+```
+
+Aside from the app-specific build parameters (`name`, `src`, `release` and
+keystore parameters), the `buildApp {}` function supports all the function
+parameters that the SDK composition function (the function shown in the
+previous section) supports.
+
+This build function is particularly useful when it is desired to use
+[Hydra](http://nixos.org/hydra): the Nix-based continuous integration solution
+to build Android apps. An Android APK gets exposed as a build product and can be
+installed on any Android device with a web browser by navigating to the build
+result page.
+
+Spawning emulator instances
+---------------------------
+For testing purposes, it can also be quite convenient to automatically generate
+scripts that spawn emulator instances with all desired configuration settings.
+
+An emulator spawn script can be configured by invoking the `emulateApp {}`
+function:
+
+```nix
+with import <nixpkgs> {};
+
+androidenv.emulateApp {
+  name = "emulate-MyAndroidApp";
+  platformVersion = "24";
+  abiVersion = "armeabi-v7a"; # mips, x86 or x86_64
+  systemImageType = "default";
+  useGoogleAPIs = false;
+}
+```
+
+It is also possible to specify an APK to deploy inside the emulator
+and the package and activity names to launch it:
+
+```nix
+with import <nixpkgs> {};
+
+androidenv.emulateApp {
+  name = "emulate-MyAndroidApp";
+  platformVersion = "24";
+  abiVersion = "armeabi-v7a"; # mips, x86 or x86_64
+  systemImageType = "default";
+  useGoogleAPIs = false;
+  app = ./MyApp.apk;
+  package = "MyApp";
+  activity = "MainActivity";
+}
+```
+
+In addition to prebuilt APKs, you can also bind the APK parameter to a
+`buildApp {}` function invocation shown in the previous example.
+
+Querying the available versions of each plugin
+----------------------------------------------
+When using any of the previously shown functions, it may be a bit inconvenient
+to find out what options are supported, since the Android SDK provides many
+plugins.
+
+A shell script in the `pkgs/development/mobile/androidenv/` sub directory can be used to retrieve all
+possible options:
+
+```bash
+sh ./querypackages.sh packages build-tools
+```
+
+The above command-line instruction queries all build-tools versions in the
+generated `packages.nix` expression.
+
+Updating the generated expressions
+----------------------------------
+Most of the Nix expressions are generated from XML files that the Android
+package manager uses. To update the expressions run the `generate.sh` script
+that is stored in the `pkgs/development/mobile/androidenv/` sub directory:
+
+```bash
+sh ./generate.sh
+```
diff --git a/nixpkgs/doc/languages-frameworks/beam.xml b/nixpkgs/doc/languages-frameworks/beam.xml
new file mode 100644
index 000000000000..ac7a83ed4265
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/beam.xml
@@ -0,0 +1,528 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-beam">
+ <title>BEAM Languages (Erlang, Elixir &amp; LFE)</title>
+
+ <section xml:id="beam-introduction">
+  <title>Introduction</title>
+
+  <para>
+   In this document and related Nix expressions, we use the term,
+   <emphasis>BEAM</emphasis>, to describe the environment. BEAM is the name of
+   the Erlang Virtual Machine and, as far as we're concerned, from a packaging
+   perspective, all languages that run on the BEAM are interchangeable. That
+   which varies, like the build system, is transparent to users of any given
+   BEAM package, so we make no distinction.
+  </para>
+ </section>
+
+ <section xml:id="beam-structure">
+  <title>Structure</title>
+
+  <para>
+   All BEAM-related expressions are available via the top-level
+   <literal>beam</literal> attribute, which includes:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     <literal>interpreters</literal>: a set of compilers running on the BEAM,
+     including multiple Erlang/OTP versions
+     (<literal>beam.interpreters.erlangR19</literal>, etc), Elixir
+     (<literal>beam.interpreters.elixir</literal>) and LFE
+     (<literal>beam.interpreters.lfe</literal>).
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     <literal>packages</literal>: a set of package sets, each compiled with a
+     specific Erlang/OTP version, e.g.
+     <literal>beam.packages.erlangR19</literal>.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <para>
+   The default Erlang compiler, defined by
+   <literal>beam.interpreters.erlang</literal>, is aliased as
+   <literal>erlang</literal>. The default BEAM package set is defined by
+   <literal>beam.packages.erlang</literal> and aliased at the top level as
+   <literal>beamPackages</literal>.
+  </para>
+
+  <para>
+   To create a package set built with a custom Erlang version, use the lambda,
+   <literal>beam.packagesWith</literal>, which accepts an Erlang/OTP derivation
+   and produces a package set similar to
+   <literal>beam.packages.erlang</literal>.
+  </para>
+
+  <para>
+   Many Erlang/OTP distributions available in
+   <literal>beam.interpreters</literal> have versions with ODBC and/or Java
+   enabled. For example, there's
+   <literal>beam.interpreters.erlangR19_odbc_javac</literal>, which corresponds
+   to <literal>beam.interpreters.erlangR19</literal>.
+  </para>
+
+  <para xml:id="erlang-call-package">
+   We also provide the lambda,
+   <literal>beam.packages.erlang.callPackage</literal>, which simplifies
+   writing BEAM package definitions by injecting all packages from
+   <literal>beam.packages.erlang</literal> into the top-level context.
+  </para>
+ </section>
+
+ <section xml:id="build-tools">
+  <title>Build Tools</title>
+
+  <section xml:id="build-tools-rebar3">
+   <title>Rebar3</title>
+
+   <para>
+    By default, Rebar3 wants to manage its own dependencies. This is perfectly
+    acceptable in the normal, non-Nix setup, but in the Nix world, it is not.
+    To rectify this, we provide two versions of Rebar3:
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>rebar3</literal>: patched to remove the ability to download
+       anything. When not running it via <literal>nix-shell</literal> or
+       <literal>nix-build</literal>, it's probably not going to work as
+       desired.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       <literal>rebar3-open</literal>: the normal, unmodified Rebar3. It should
+       work exactly as would any other version of Rebar3. Any Erlang package
+       should rely on <literal>rebar3</literal> instead. See
+       <xref
+            linkend="rebar3-packages"/>.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </para>
+  </section>
+
+  <section xml:id="build-tools-other">
+   <title>Mix &amp; Erlang.mk</title>
+
+   <para>
+    Both Mix and Erlang.mk work exactly as expected. There is a bootstrap
+    process that needs to be run for both, however, which is supported by the
+    <literal>buildMix</literal> and <literal>buildErlangMk</literal>
+    derivations, respectively.
+   </para>
+  </section>
+ </section>
+
+ <section xml:id="how-to-install-beam-packages">
+  <title>How to Install BEAM Packages</title>
+
+  <para>
+   BEAM packages are not registered at the top level, simply because they are
+   not relevant to the vast majority of Nix users. They are installable using
+   the <literal>beam.packages.erlang</literal> attribute set (aliased as
+   <literal>beamPackages</literal>), which points to packages built by the
+   default Erlang/OTP version in Nixpkgs, as defined by
+   <literal>beam.interpreters.erlang</literal>. To list the available packages
+   in <literal>beamPackages</literal>, use the following command:
+  </para>
+
+<programlisting>
+$ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -qaP -A beamPackages
+beamPackages.esqlite    esqlite-0.2.1
+beamPackages.goldrush   goldrush-0.1.7
+beamPackages.ibrowse    ibrowse-4.2.2
+beamPackages.jiffy      jiffy-0.14.5
+beamPackages.lager      lager-3.0.2
+beamPackages.meck       meck-0.8.3
+beamPackages.rebar3-pc  pc-1.1.0
+  </programlisting>
+
+  <para>
+   To install any of those packages into your profile, refer to them by their
+   attribute path (first column):
+  </para>
+
+<programlisting>
+$ nix-env -f &quot;&lt;nixpkgs&gt;&quot; -iA beamPackages.ibrowse
+  </programlisting>
+
+  <para>
+   The attribute path of any BEAM package corresponds to the name of that
+   particular package in <link xlink:href="https://hex.pm">Hex</link> or its
+   OTP Application/Release name.
+  </para>
+ </section>
+
+ <section xml:id="packaging-beam-applications">
+  <title>Packaging BEAM Applications</title>
+
+  <section  xml:id="packaging-erlang-applications">
+   <title>Erlang Applications</title>
+
+   <section xml:id="rebar3-packages">
+    <title>Rebar3 Packages</title>
+
+    <para>
+     The Nix function, <literal>buildRebar3</literal>, defined in
+     <literal>beam.packages.erlang.buildRebar3</literal> and aliased at the top
+     level, can be used to build a derivation that understands how to build a
+     Rebar3 project. For example, we can build
+     <link
+        xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>
+     as follows:
+    </para>
+
+<programlisting>
+        { stdenv, fetchFromGitHub, buildRebar3, ibrowse, jsx, erlware_commons }:
+
+        buildRebar3 rec {
+          name = "hex2nix";
+          version = "0.0.1";
+
+          src = fetchFromGitHub {
+            owner = "ericbmerritt";
+            repo = "hex2nix";
+            rev = "${version}";
+            sha256 = "1w7xjidz1l5yjmhlplfx7kphmnpvqm67w99hd2m7kdixwdxq0zqg";
+          };
+
+          beamDeps = [ ibrowse jsx erlware_commons ];
+        }
+      </programlisting>
+
+    <para>
+     Such derivations are callable with
+     <literal>beam.packages.erlang.callPackage</literal> (see
+     <xref
+        linkend="erlang-call-package"/>). To call this package using
+     the normal <literal>callPackage</literal>, refer to dependency packages
+     via <literal>beamPackages</literal>, e.g.
+     <literal>beamPackages.ibrowse</literal>.
+    </para>
+
+    <para>
+     Notably, <literal>buildRebar3</literal> includes
+     <literal>beamDeps</literal>, while <literal>stdenv.mkDerivation</literal>
+     does not. BEAM dependencies added there will be correctly handled by the
+     system.
+    </para>
+
+    <para>
+     If a package needs to compile native code via Rebar3's port compilation
+     mechanism, add <literal>compilePort = true;</literal> to the derivation.
+    </para>
+   </section>
+
+   <section xml:id="erlang-mk-packages">
+    <title>Erlang.mk Packages</title>
+
+    <para>
+     Erlang.mk functions similarly to Rebar3, except we use
+     <literal>buildErlangMk</literal> instead of
+     <literal>buildRebar3</literal>.
+    </para>
+
+<programlisting>
+        { buildErlangMk, fetchHex, cowlib, ranch }:
+
+        buildErlangMk {
+          name = "cowboy";
+          version = "1.0.4";
+
+          src = fetchHex {
+            pkg = "cowboy";
+            version = "1.0.4";
+            sha256 = "6a0edee96885fae3a8dd0ac1f333538a42e807db638a9453064ccfdaa6b9fdac";
+          };
+
+          beamDeps = [ cowlib ranch ];
+
+          meta = {
+            description = ''
+              Small, fast, modular HTTP server written in Erlang
+            '';
+            license = stdenv.lib.licenses.isc;
+            homepage = https://github.com/ninenines/cowboy;
+          };
+        }
+      </programlisting>
+   </section>
+
+   <section xml:id="mix-packages">
+    <title>Mix Packages</title>
+
+    <para>
+     Mix functions similarly to Rebar3, except we use
+     <literal>buildMix</literal> instead of <literal>buildRebar3</literal>.
+    </para>
+
+<programlisting>
+        { buildMix, fetchHex, plug, absinthe }:
+
+        buildMix {
+          name = "absinthe_plug";
+          version = "1.0.0";
+
+          src = fetchHex {
+            pkg = "absinthe_plug";
+            version = "1.0.0";
+            sha256 = "08459823fe1fd4f0325a8bf0c937a4520583a5a26d73b193040ab30a1dfc0b33";
+          };
+
+          beamDeps = [ plug absinthe ];
+
+          meta = {
+            description = ''
+              A plug for Absinthe, an experimental GraphQL toolkit
+            '';
+            license = stdenv.lib.licenses.bsd3;
+            homepage = https://github.com/CargoSense/absinthe_plug;
+          };
+        }
+      </programlisting>
+
+    <para>
+     Alternatively, we can use <literal>buildHex</literal> as a shortcut:
+    </para>
+
+<programlisting>
+        { buildHex, buildMix, plug, absinthe }:
+
+        buildHex {
+          name = "absinthe_plug";
+          version = "1.0.0";
+
+          sha256 = "08459823fe1fd4f0325a8bf0c937a4520583a5a26d73b193040ab30a1dfc0b33";
+
+          builder = buildMix;
+
+          beamDeps = [ plug absinthe ];
+
+          meta = {
+            description = ''
+              A plug for Absinthe, an experimental GraphQL toolkit
+            '';
+            license = stdenv.lib.licenses.bsd3;
+            homepage = https://github.com/CargoSense/absinthe_plug;
+         };
+       }
+      </programlisting>
+   </section>
+  </section>
+ </section>
+
+ <section xml:id="how-to-develop">
+  <title>How to Develop</title>
+
+  <section xml:id="accessing-an-environment">
+   <title>Accessing an Environment</title>
+
+   <para>
+    Often, we simply want to access a valid environment that contains a
+    specific package and its dependencies. We can accomplish that with the
+    <literal>env</literal> attribute of a derivation. For example, let's say we
+    want to access an Erlang REPL with <literal>ibrowse</literal> loaded up. We
+    could do the following:
+   </para>
+
+<programlisting>
+      $ nix-shell -A beamPackages.ibrowse.env --run "erl"
+      Erlang/OTP 18 [erts-7.0] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false]
+
+      Eshell V7.0  (abort with ^G)
+      1> m(ibrowse).
+      Module: ibrowse
+      MD5: 3b3e0137d0cbb28070146978a3392945
+      Compiled: January 10 2016, 23:34
+      Object file: /nix/store/g1rlf65rdgjs4abbyj4grp37ry7ywivj-ibrowse-4.2.2/lib/erlang/lib/ibrowse-4.2.2/ebin/ibrowse.beam
+      Compiler options:  [{outdir,"/tmp/nix-build-ibrowse-4.2.2.drv-0/hex-source-ibrowse-4.2.2/_build/default/lib/ibrowse/ebin"},
+      debug_info,debug_info,nowarn_shadow_vars,
+      warn_unused_import,warn_unused_vars,warnings_as_errors,
+      {i,"/tmp/nix-build-ibrowse-4.2.2.drv-0/hex-source-ibrowse-4.2.2/_build/default/lib/ibrowse/include"}]
+      Exports:
+      add_config/1                  send_req_direct/7
+      all_trace_off/0               set_dest/3
+      code_change/3                 set_max_attempts/3
+      get_config_value/1            set_max_pipeline_size/3
+      get_config_value/2            set_max_sessions/3
+      get_metrics/0                 show_dest_status/0
+      get_metrics/2                 show_dest_status/1
+      handle_call/3                 show_dest_status/2
+      handle_cast/2                 spawn_link_worker_process/1
+      handle_info/2                 spawn_link_worker_process/2
+      init/1                        spawn_worker_process/1
+      module_info/0                 spawn_worker_process/2
+      module_info/1                 start/0
+      rescan_config/0               start_link/0
+      rescan_config/1               stop/0
+      send_req/3                    stop_worker_process/1
+      send_req/4                    stream_close/1
+      send_req/5                    stream_next/1
+      send_req/6                    terminate/2
+      send_req_direct/4             trace_off/0
+      send_req_direct/5             trace_off/2
+      send_req_direct/6             trace_on/0
+      trace_on/2
+      ok
+      2>
+    </programlisting>
+
+   <para>
+    Notice the <literal>-A beamPackages.ibrowse.env</literal>. That is the key
+    to this functionality.
+   </para>
+  </section>
+
+  <section xml:id="creating-a-shell">
+   <title>Creating a Shell</title>
+
+   <para>
+    Getting access to an environment often isn't enough to do real development.
+    Usually, we need to create a <literal>shell.nix</literal> file and do our
+    development inside of the environment specified therein. This file looks a
+    lot like the packaging described above, except that <literal>src</literal>
+    points to the project root and we call the package directly.
+   </para>
+
+<programlisting>
+{ pkgs ? import &quot;&lt;nixpkgs&quot;&gt; {} }:
+
+with pkgs;
+
+let
+
+  f = { buildRebar3, ibrowse, jsx, erlware_commons }:
+      buildRebar3 {
+        name = "hex2nix";
+        version = "0.1.0";
+        src = ./.;
+        beamDeps = [ ibrowse jsx erlware_commons ];
+      };
+  drv = beamPackages.callPackage f {};
+
+in
+
+  drv
+    </programlisting>
+
+   <section xml:id="building-in-a-shell">
+    <title>Building in a Shell (for Mix Projects)</title>
+
+    <para>
+     We can leverage the support of the derivation, irrespective of the build
+     derivation, by calling the commands themselves.
+    </para>
+
+<programlisting>
+# =============================================================================
+# Variables
+# =============================================================================
+
+NIX_TEMPLATES := "$(CURDIR)/nix-templates"
+
+TARGET := "$(PREFIX)"
+
+PROJECT_NAME := thorndyke
+
+NIXPKGS=../nixpkgs
+NIX_PATH=nixpkgs=$(NIXPKGS)
+NIX_SHELL=nix-shell -I "$(NIX_PATH)" --pure
+# =============================================================================
+# Rules
+# =============================================================================
+.PHONY= all test clean repl shell build test analyze configure install \
+        test-nix-install publish plt analyze
+
+all: build
+
+guard-%:
+        @ if [ "${${*}}" == "" ]; then \
+                echo "Environment variable $* not set"; \
+                exit 1; \
+        fi
+
+clean:
+        rm -rf _build
+        rm -rf .cache
+
+repl:
+        $(NIX_SHELL) --run "iex -pa './_build/prod/lib/*/ebin'"
+
+shell:
+        $(NIX_SHELL)
+
+configure:
+        $(NIX_SHELL) --command 'eval "$$configurePhase"'
+
+build: configure
+        $(NIX_SHELL) --command 'eval "$$buildPhase"'
+
+install:
+        $(NIX_SHELL) --command 'eval "$$installPhase"'
+
+test:
+        $(NIX_SHELL) --command 'mix test --no-start --no-deps-check'
+
+plt:
+        $(NIX_SHELL) --run "mix dialyzer.plt --no-deps-check"
+
+analyze: build plt
+        $(NIX_SHELL) --run "mix dialyzer --no-compile"
+
+    </programlisting>
+
+    <para>
+     Using a <literal>shell.nix</literal> as described (see
+     <xref
+      linkend="creating-a-shell"/>) should just work. Aside from
+     <literal>test</literal>, <literal>plt</literal>, and
+     <literal>analyze</literal>, the Make targets work just fine for all of the
+     build derivations.
+    </para>
+   </section>
+  </section>
+ </section>
+
+ <section xml:id="generating-packages-from-hex-with-hex2nix">
+  <title>Generating Packages from Hex with <literal>hex2nix</literal></title>
+
+  <para>
+   Updating the <link xlink:href="https://hex.pm">Hex</link> package set
+   requires
+   <link
+    xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>.
+   Given the path to the Erlang modules (usually
+   <literal>pkgs/development/erlang-modules</literal>), it will dump a file
+   called <literal>hex-packages.nix</literal>, containing all the packages that
+   use a recognized build system in
+   <link
+    xlink:href="https://hex.pm">Hex</link>. It can't be determined,
+   however, whether every package is buildable.
+  </para>
+
+  <para>
+   To make life easier for our users, try to build every
+   <link
+      xlink:href="https://hex.pm">Hex</link> package and remove those
+   that fail. To do that, simply run the following command in the root of your
+   <literal>nixpkgs</literal> repository:
+  </para>
+
+<programlisting>
+$ nix-build -A beamPackages
+    </programlisting>
+
+  <para>
+   That will attempt to build every package in <literal>beamPackages</literal>.
+   Then manually remove those that fail. Hopefully, someone will improve
+   <link
+      xlink:href="https://github.com/erlang-nix/hex2nix">hex2nix</link>
+   in the future to automate the process.
+  </para>
+ </section>
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/bower.xml b/nixpkgs/doc/languages-frameworks/bower.xml
new file mode 100644
index 000000000000..118f6e10473a
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/bower.xml
@@ -0,0 +1,229 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-bower">
+ <title>Bower</title>
+
+ <para>
+  <link xlink:href="http://bower.io">Bower</link> is a package manager for web
+  site front-end components. Bower packages (comprising of build artefacts and
+  sometimes sources) are stored in <command>git</command> repositories,
+  typically on Github. The package registry is run by the Bower team with
+  package metadata coming from the <filename>bower.json</filename> file within
+  each package.
+ </para>
+
+ <para>
+  The end result of running Bower is a <filename>bower_components</filename>
+  directory which can be included in the web app's build process.
+ </para>
+
+ <para>
+  Bower can be run interactively, by installing
+  <varname>nodePackages.bower</varname>. More interestingly, the Bower
+  components can be declared in a Nix derivation, with the help of
+  <varname>nodePackages.bower2nix</varname>.
+ </para>
+
+ <section xml:id="ssec-bower2nix-usage">
+  <title><command>bower2nix</command> usage</title>
+
+  <para>
+   Suppose you have a <filename>bower.json</filename> with the following
+   contents:
+   <example xml:id="ex-bowerJson">
+    <title><filename>bower.json</filename></title>
+<programlisting language="json">
+<![CDATA[{
+  "name": "my-web-app",
+  "dependencies": {
+    "angular": "~1.5.0",
+    "bootstrap": "~3.3.6"
+  }
+}]]>
+</programlisting>
+   </example>
+  </para>
+
+  <para>
+   Running <command>bower2nix</command> will produce something like the
+   following output:
+<programlisting language="nix">
+<![CDATA[{ fetchbower, buildEnv }:
+buildEnv { name = "bower-env"; ignoreCollisions = true; paths = [
+  (fetchbower "angular" "1.5.3" "~1.5.0" "1749xb0firxdra4rzadm4q9x90v6pzkbd7xmcyjk6qfza09ykk9y")
+  (fetchbower "bootstrap" "3.3.6" "~3.3.6" "1vvqlpbfcy0k5pncfjaiskj3y6scwifxygfqnw393sjfxiviwmbv")
+  (fetchbower "jquery" "2.2.2" "1.9.1 - 2" "10sp5h98sqwk90y4k6hbdviwqzvzwqf47r3r51pakch5ii2y7js1")
+]; }]]>
+</programlisting>
+  </para>
+
+  <para>
+   Using the <command>bower2nix</command> command line arguments, the output
+   can be redirected to a file. A name like
+   <filename>bower-packages.nix</filename> would be fine.
+  </para>
+
+  <para>
+   The resulting derivation is a union of all the downloaded Bower packages
+   (and their dependencies). To use it, they still need to be linked together
+   by Bower, which is where <varname>buildBowerComponents</varname> is useful.
+  </para>
+ </section>
+
+ <section xml:id="ssec-build-bower-components">
+  <title><varname>buildBowerComponents</varname> function</title>
+
+  <para>
+   The function is implemented in
+   <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/bower-modules/generic/default.nix">
+   <filename>pkgs/development/bower-modules/generic/default.nix</filename></link>.
+   Example usage:
+   <example xml:id="ex-buildBowerComponents">
+    <title>buildBowerComponents</title>
+<programlisting language="nix">
+bowerComponents = buildBowerComponents {
+  name = "my-web-app";
+  generated = ./bower-packages.nix; <co xml:id="ex-buildBowerComponents-1" />
+  src = myWebApp; <co xml:id="ex-buildBowerComponents-2" />
+};
+</programlisting>
+   </example>
+  </para>
+
+  <para>
+   In <xref linkend="ex-buildBowerComponents" />, the following arguments are
+   of special significance to the function:
+   <calloutlist>
+    <callout arearefs="ex-buildBowerComponents-1">
+     <para>
+      <varname>generated</varname> specifies the file which was created by
+      <command>bower2nix</command>.
+     </para>
+    </callout>
+    <callout arearefs="ex-buildBowerComponents-2">
+     <para>
+      <varname>src</varname> is your project's sources. It needs to contain a
+      <filename>bower.json</filename> file.
+     </para>
+    </callout>
+   </calloutlist>
+  </para>
+
+  <para>
+   <varname>buildBowerComponents</varname> will run Bower to link together the
+   output of <command>bower2nix</command>, resulting in a
+   <filename>bower_components</filename> directory which can be used.
+  </para>
+
+  <para>
+   Here is an example of a web frontend build process using
+   <command>gulp</command>. You might use <command>grunt</command>, or anything
+   else.
+  </para>
+
+  <example xml:id="ex-bowerGulpFile">
+   <title>Example build script (<filename>gulpfile.js</filename>)</title>
+<programlisting language="javascript">
+<![CDATA[var gulp = require('gulp');
+
+gulp.task('default', [], function () {
+  gulp.start('build');
+});
+
+gulp.task('build', [], function () {
+  console.log("Just a dummy gulp build");
+  gulp
+    .src(["./bower_components/**/*"])
+    .pipe(gulp.dest("./gulpdist/"));
+});]]>
+</programlisting>
+  </example>
+
+  <example xml:id="ex-buildBowerComponentsDefaultNix">
+   <title>Full example — <filename>default.nix</filename></title>
+<programlisting language="nix">
+{ myWebApp ? { outPath = ./.; name = "myWebApp"; }
+, pkgs ? import &lt;nixpkgs&gt; {}
+}:
+
+pkgs.stdenv.mkDerivation {
+  name = "my-web-app-frontend";
+  src = myWebApp;
+
+  buildInputs = [ pkgs.nodePackages.gulp ];
+
+  bowerComponents = pkgs.buildBowerComponents { <co xml:id="ex-buildBowerComponentsDefault-1" />
+    name = "my-web-app";
+    generated = ./bower-packages.nix;
+    src = myWebApp;
+  };
+
+  buildPhase = ''
+    cp --reflink=auto --no-preserve=mode -R $bowerComponents/bower_components . <co xml:id="ex-buildBowerComponentsDefault-2" />
+    export HOME=$PWD <co xml:id="ex-buildBowerComponentsDefault-3" />
+    ${pkgs.nodePackages.gulp}/bin/gulp build <co xml:id="ex-buildBowerComponentsDefault-4" />
+  '';
+
+  installPhase = "mv gulpdist $out";
+}
+</programlisting>
+  </example>
+
+  <para>
+   A few notes about <xref linkend="ex-buildBowerComponentsDefaultNix" />:
+   <calloutlist>
+    <callout arearefs="ex-buildBowerComponentsDefault-1">
+     <para>
+      The result of <varname>buildBowerComponents</varname> is an input to the
+      frontend build.
+     </para>
+    </callout>
+    <callout arearefs="ex-buildBowerComponentsDefault-2">
+     <para>
+      Whether to symlink or copy the <filename>bower_components</filename>
+      directory depends on the build tool in use. In this case a copy is used
+      to avoid <command>gulp</command> silliness with permissions.
+     </para>
+    </callout>
+    <callout arearefs="ex-buildBowerComponentsDefault-3">
+     <para>
+      <command>gulp</command> requires <varname>HOME</varname> to refer to a
+      writeable directory.
+     </para>
+    </callout>
+    <callout arearefs="ex-buildBowerComponentsDefault-4">
+     <para>
+      The actual build command. Other tools could be used.
+     </para>
+    </callout>
+   </calloutlist>
+  </para>
+ </section>
+
+ <section xml:id="ssec-bower2nix-troubleshooting">
+  <title>Troubleshooting</title>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <literal>ENOCACHE</literal> errors from <varname>buildBowerComponents</varname>
+    </term>
+    <listitem>
+     <para>
+      This means that Bower was looking for a package version which doesn't
+      exist in the generated <filename>bower-packages.nix</filename>.
+     </para>
+     <para>
+      If <filename>bower.json</filename> has been updated, then run
+      <command>bower2nix</command> again.
+     </para>
+     <para>
+      It could also be a bug in <command>bower2nix</command> or
+      <command>fetchbower</command>. If possible, try reformulating the version
+      specification in <filename>bower.json</filename>.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+ </section>
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/coq.xml b/nixpkgs/doc/languages-frameworks/coq.xml
new file mode 100644
index 000000000000..4314df5c9df2
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/coq.xml
@@ -0,0 +1,64 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-coq">
+ <title>Coq</title>
+
+ <para>
+  Coq libraries should be installed in
+  <literal>$(out)/lib/coq/${coq.coq-version}/user-contrib/</literal>. Such
+  directories are automatically added to the <literal>$COQPATH</literal>
+  environment variable by the hook defined in the Coq derivation.
+ </para>
+
+ <para>
+  Some extensions (plugins) might require OCaml and sometimes other OCaml
+  packages. The <literal>coq.ocamlPackages</literal> attribute can be used to
+  depend on the same package set Coq was built against.
+ </para>
+
+ <para>
+  Coq libraries may be compatible with some specific versions of Coq only. The
+  <literal>compatibleCoqVersions</literal> attribute is used to precisely
+  select those versions of Coq that are compatible with this derivation.
+ </para>
+
+ <para>
+  Here is a simple package example. It is a pure Coq library, thus it depends
+  on Coq. It builds on the Mathematical Components library, thus it also takes
+  <literal>mathcomp</literal> as <literal>buildInputs</literal>. Its
+  <literal>Makefile</literal> has been generated using
+  <literal>coq_makefile</literal> so we only have to set the
+  <literal>$COQLIB</literal> variable at install time.
+ </para>
+
+<programlisting>
+{ stdenv, fetchFromGitHub, coq, mathcomp }:
+
+stdenv.mkDerivation rec {
+  name = "coq${coq.coq-version}-multinomials-${version}";
+  version = "1.0";
+  src = fetchFromGitHub {
+    owner = "math-comp";
+    repo = "multinomials";
+    rev = version;
+    sha256 = "1qmbxp1h81cy3imh627pznmng0kvv37k4hrwi2faa101s6bcx55m";
+  };
+
+  buildInputs = [ coq ];
+  propagatedBuildInputs = [ mathcomp ];
+
+  installFlags = "COQLIB=$(out)/lib/coq/${coq.coq-version}/";
+
+  meta = {
+    description = "A Coq/SSReflect Library for Monoidal Rings and Multinomials";
+    inherit (src.meta) homepage;
+    license = stdenv.lib.licenses.cecill-b;
+    inherit (coq.meta) platforms;
+  };
+
+  passthru = {
+    compatibleCoqVersions = v: builtins.elem v [ "8.5" "8.6" "8.7" ];
+  };
+}
+</programlisting>
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/emscripten.section.md b/nixpkgs/doc/languages-frameworks/emscripten.section.md
new file mode 100644
index 000000000000..24c49ec1409c
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/emscripten.section.md
@@ -0,0 +1,185 @@
+# User's Guide to Emscripten in Nixpkgs
+
+[Emscripten](https://github.com/kripken/emscripten): An LLVM-to-JavaScript Compiler
+
+This section of the manual covers how to use `emscripten` in nixpkgs.
+
+Minimal requirements:
+
+* nix
+* nixpkgs
+
+Modes of use of `emscripten`:
+
+* **Imperative usage** (on the command line):
+
+   If you want to work with `emcc`, `emconfigure` and `emmake` as you are used to from Ubuntu and similar distributions you can use these commands:
+
+    * `nix-env -i emscripten`
+    * `nix-shell -p emscripten`
+
+* **Declarative usage**:
+
+    This mode is far more power full since this makes use of `nix` for dependency management of emscripten libraries and targets by using the `mkDerivation` which is implemented by `pkgs.emscriptenStdenv` and `pkgs.buildEmscriptenPackage`. The source for the packages is in `pkgs/top-level/emscripten-packages.nix` and the abstraction behind it in `pkgs/development/em-modules/generic/default.nix`.
+    * build and install all packages: 
+        * `nix-env -iA emscriptenPackages` 
+          
+    * dev-shell for zlib implementation hacking: 
+        * `nix-shell -A emscriptenPackages.zlib` 
+
+
+## Imperative usage
+
+A few things to note:
+
+* `export EMCC_DEBUG=2` is nice for debugging
+* `~/.emscripten`, the build artifact cache sometimes creates issues and needs to be removed from time to time
+
+
+## Declarative usage
+
+Let's see two different examples from `pkgs/top-level/emscripten-packages.nix`:
+
+* `pkgs.zlib.override`
+* `pkgs.buildEmscriptenPackage`
+
+Both are interesting concepts.
+
+A special requirement of the `pkgs.buildEmscriptenPackage` is the `doCheck = true` is a default meaning that each emscriptenPackage requires a `checkPhase` implemented.
+
+* Use `export EMCC_DEBUG=2` from within a emscriptenPackage's `phase` to get more detailed debug output what is going wrong.
+* ~/.emscripten cache is requiring us to set `HOME=$TMPDIR` in individual phases. This makes compilation slower but also makes it more deterministic.
+
+### Usage 1: pkgs.zlib.override
+
+This example uses `zlib` from nixpkgs but instead of compiling **C** to **ELF** it compiles **C** to **JS** since we were using `pkgs.zlib.override` and changed stdenv to `pkgs.emscriptenStdenv`. A few adaptions and hacks were set in place to make it working. One advantage is that when `pkgs.zlib` is updated, it will automatically update this package as well. However, this can also be the downside...
+
+See the `zlib` example:
+
+    zlib = (pkgs.zlib.override {
+      stdenv = pkgs.emscriptenStdenv;
+    }).overrideDerivation
+    (old: rec {
+      buildInputs = old.buildInputs ++ [ pkgconfig ];
+      # we need to reset this setting!
+      NIX_CFLAGS_COMPILE="";
+      configurePhase = ''
+        # FIXME: Some tests require writing at $HOME
+        HOME=$TMPDIR
+        runHook preConfigure
+
+        #export EMCC_DEBUG=2
+        emconfigure ./configure --prefix=$out --shared
+
+        runHook postConfigure
+      '';
+      dontStrip = true;
+      outputs = [ "out" ];
+      buildPhase = ''
+        emmake make
+      '';
+      installPhase = ''
+        emmake make install
+      '';
+      checkPhase = ''
+        echo "================= testing zlib using node ================="
+
+        echo "Compiling a custom test"
+        set -x
+        emcc -O2 -s EMULATE_FUNCTION_POINTER_CASTS=1 test/example.c -DZ_SOLO \
+        libz.so.${old.version} -I . -o example.js
+
+        echo "Using node to execute the test"
+        ${pkgs.nodejs}/bin/node ./example.js 
+
+        set +x
+        if [ $? -ne 0 ]; then
+          echo "test failed for some reason"
+          exit 1;
+        else
+          echo "it seems to work! very good."
+        fi
+        echo "================= /testing zlib using node ================="
+      '';
+
+      postPatch = pkgs.stdenv.lib.optionalString pkgs.stdenv.isDarwin ''
+        substituteInPlace configure \
+          --replace '/usr/bin/libtool' 'ar' \
+          --replace 'AR="libtool"' 'AR="ar"' \
+          --replace 'ARFLAGS="-o"' 'ARFLAGS="-r"'
+      '';
+    });
+
+### Usage 2: pkgs.buildEmscriptenPackage
+
+This `xmlmirror` example features a emscriptenPackage which is defined completely from this context and no `pkgs.zlib.override` is used. 
+
+    xmlmirror = pkgs.buildEmscriptenPackage rec {
+      name = "xmlmirror";
+
+      buildInputs = [ pkgconfig autoconf automake libtool gnumake libxml2 nodejs openjdk json_c ];
+      nativeBuildInputs = [ pkgconfig zlib ];
+
+      src = pkgs.fetchgit {
+        url = "https://gitlab.com/odfplugfest/xmlmirror.git";
+        rev = "4fd7e86f7c9526b8f4c1733e5c8b45175860a8fd";
+        sha256 = "1jasdqnbdnb83wbcnyrp32f36w3xwhwp0wq8lwwmhqagxrij1r4b";
+      };
+
+      configurePhase = ''
+        rm -f fastXmlLint.js*
+        # a fix for ERROR:root:For asm.js, TOTAL_MEMORY must be a multiple of 16MB, was 234217728
+        # https://gitlab.com/odfplugfest/xmlmirror/issues/8
+        sed -e "s/TOTAL_MEMORY=234217728/TOTAL_MEMORY=268435456/g" -i Makefile.emEnv
+        # https://github.com/kripken/emscripten/issues/6344
+        # https://gitlab.com/odfplugfest/xmlmirror/issues/9
+        sed -e "s/\$(JSONC_LDFLAGS) \$(ZLIB_LDFLAGS) \$(LIBXML20_LDFLAGS)/\$(JSONC_LDFLAGS) \$(LIBXML20_LDFLAGS) \$(ZLIB_LDFLAGS) /g" -i Makefile.emEnv
+        # https://gitlab.com/odfplugfest/xmlmirror/issues/11
+        sed -e "s/-o fastXmlLint.js/-s EXTRA_EXPORTED_RUNTIME_METHODS='[\"ccall\", \"cwrap\"]' -o fastXmlLint.js/g" -i Makefile.emEnv
+      '';
+
+      buildPhase = ''
+        HOME=$TMPDIR
+        make -f Makefile.emEnv
+      '';
+
+      outputs = [ "out" "doc" ];
+
+      installPhase = ''
+        mkdir -p $out/share
+        mkdir -p $doc/share/${name}
+
+        cp Demo* $out/share
+        cp -R codemirror-5.12 $out/share
+        cp fastXmlLint.js* $out/share
+        cp *.xsd $out/share
+        cp *.js $out/share
+        cp *.xhtml $out/share
+        cp *.html $out/share
+        cp *.json $out/share
+        cp *.rng $out/share
+        cp README.md $doc/share/${name}
+      '';
+      checkPhase = ''
+
+      '';
+    }; 
+
+### Declarative debugging
+
+Use `nix-shell -I nixpkgs=/some/dir/nixpkgs -A emscriptenPackages.libz` and from there you can go trough the individual steps. This makes it easy to build a good `unit test` or list the files of the project.
+
+1. `nix-shell -I nixpkgs=/some/dir/nixpkgs -A emscriptenPackages.libz`
+2. `cd /tmp/`
+3. `unpackPhase`
+4. cd libz-1.2.3
+5. `configurePhase`
+6. `buildPhase`
+7. ... happy hacking...
+
+## Summary
+
+Using this toolchain makes it easy to leverage `nix` from NixOS, MacOSX or even Windows (WSL+ubuntu+nix). This toolchain is reproducible, behaves like the rest of the packages from nixpkgs and contains a set of well working examples to learn and adapt from.
+
+If in trouble, ask the maintainers.
+
diff --git a/nixpkgs/doc/languages-frameworks/go.xml b/nixpkgs/doc/languages-frameworks/go.xml
new file mode 100644
index 000000000000..ab4c9f0f7c88
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/go.xml
@@ -0,0 +1,160 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-go">
+ <title>Go</title>
+
+ <para>
+  The function <varname>buildGoPackage</varname> builds standard Go programs.
+ </para>
+
+ <example xml:id='ex-buildGoPackage'>
+  <title>buildGoPackage</title>
+<programlisting>
+deis = buildGoPackage rec {
+  name = "deis-${version}";
+  version = "1.13.0";
+
+  goPackagePath = "github.com/deis/deis"; <co xml:id='ex-buildGoPackage-1' />
+  subPackages = [ "client" ]; <co xml:id='ex-buildGoPackage-2' />
+
+  src = fetchFromGitHub {
+    owner = "deis";
+    repo = "deis";
+    rev = "v${version}";
+    sha256 = "1qv9lxqx7m18029lj8cw3k7jngvxs4iciwrypdy0gd2nnghc68sw";
+  };
+
+  goDeps = ./deps.nix; <co xml:id='ex-buildGoPackage-3' />
+
+  buildFlags = "--tags release"; <co xml:id='ex-buildGoPackage-4' />
+}
+</programlisting>
+ </example>
+
+ <para>
+  <xref linkend='ex-buildGoPackage'/> is an example expression using
+  buildGoPackage, the following arguments are of special significance to the
+  function:
+  <calloutlist>
+   <callout arearefs='ex-buildGoPackage-1'>
+    <para>
+     <varname>goPackagePath</varname> specifies the package's canonical Go
+     import path.
+    </para>
+   </callout>
+   <callout arearefs='ex-buildGoPackage-2'>
+    <para>
+     <varname>subPackages</varname> limits the builder from building child
+     packages that have not been listed. If <varname>subPackages</varname> is
+     not specified, all child packages will be built.
+    </para>
+    <para>
+     In this example only <literal>github.com/deis/deis/client</literal> will
+     be built.
+    </para>
+   </callout>
+   <callout arearefs='ex-buildGoPackage-3'>
+    <para>
+     <varname>goDeps</varname> is where the Go dependencies of a Go program are
+     listed as a list of package source identified by Go import path. It could
+     be imported as a separate <varname>deps.nix</varname> file for
+     readability. The dependency data structure is described below.
+    </para>
+   </callout>
+   <callout arearefs='ex-buildGoPackage-4'>
+    <para>
+     <varname>buildFlags</varname> is a list of flags passed to the go build
+     command.
+    </para>
+   </callout>
+  </calloutlist>
+ </para>
+
+ <para>
+  The <varname>goDeps</varname> attribute can be imported from a separate
+  <varname>nix</varname> file that defines which Go libraries are needed and
+  should be included in <varname>GOPATH</varname> for
+  <varname>buildPhase</varname>.
+ </para>
+
+ <example xml:id='ex-goDeps'>
+  <title>deps.nix</title>
+<programlisting>
+[ <co xml:id='ex-goDeps-1' />
+  {
+    goPackagePath = "gopkg.in/yaml.v2"; <co xml:id='ex-goDeps-2' />
+    fetch = {
+      type = "git"; <co xml:id='ex-goDeps-3' />
+      url = "https://gopkg.in/yaml.v2";
+      rev = "a83829b6f1293c91addabc89d0571c246397bbf4";
+      sha256 = "1m4dsmk90sbi17571h6pld44zxz7jc4lrnl4f27dpd1l8g5xvjhh";
+    };
+  }
+  {
+    goPackagePath = "github.com/docopt/docopt-go";
+    fetch = {
+      type = "git";
+      url = "https://github.com/docopt/docopt-go";
+      rev = "784ddc588536785e7299f7272f39101f7faccc3f";
+      sha256 = "0wwz48jl9fvl1iknvn9dqr4gfy1qs03gxaikrxxp9gry6773v3sj";
+    };
+  }
+]
+</programlisting>
+ </example>
+
+ <para>
+  <calloutlist>
+   <callout arearefs='ex-goDeps-1'>
+    <para>
+     <varname>goDeps</varname> is a list of Go dependencies.
+    </para>
+   </callout>
+   <callout arearefs='ex-goDeps-2'>
+    <para>
+     <varname>goPackagePath</varname> specifies Go package import path.
+    </para>
+   </callout>
+   <callout arearefs='ex-goDeps-3'>
+    <para>
+     <varname>fetch type</varname> that needs to be used to get package source.
+     If <varname>git</varname> is used there should be <varname>url</varname>,
+     <varname>rev</varname> and <varname>sha256</varname> defined next to it.
+    </para>
+   </callout>
+  </calloutlist>
+ </para>
+
+ <para>
+  To extract dependency information from a Go package in automated way use
+  <link xlink:href="https://github.com/kamilchm/go2nix">go2nix</link>. It can
+  produce complete derivation and <varname>goDeps</varname> file for Go
+  programs.
+ </para>
+
+ <para>
+  <varname>buildGoPackage</varname> produces
+  <xref linkend='chap-multiple-output' xrefstyle="select: title" /> where
+  <varname>bin</varname> includes program binaries. You can test build a Go
+  binary as follows:
+<screen>
+    $ nix-build -A deis.bin
+  </screen>
+  or build all outputs with:
+<screen>
+    $ nix-build -A deis.all
+  </screen>
+  <varname>bin</varname> output will be installed by default with
+  <varname>nix-env -i</varname> or <varname>systemPackages</varname>.
+ </para>
+
+ <para>
+  You may use Go packages installed into the active Nix profiles by adding the
+  following to your ~/.bashrc:
+<screen>
+for p in $NIX_PROFILES; do
+    GOPATH="$p/share/go:$GOPATH"
+done
+</screen>
+ </para>
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/haskell.section.md b/nixpkgs/doc/languages-frameworks/haskell.section.md
new file mode 100644
index 000000000000..74b7a9f961ee
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/haskell.section.md
@@ -0,0 +1,1091 @@
+---
+title: User's Guide for Haskell in Nixpkgs
+author: Peter Simons
+date: 2015-06-01
+---
+# User's Guide to the Haskell Infrastructure
+
+
+## How to install Haskell packages
+
+Nixpkgs distributes build instructions for all Haskell packages registered on
+[Hackage](http://hackage.haskell.org/), but strangely enough normal Nix package
+lookups don't seem to discover any of them, except for the default version of ghc, cabal-install, and stack:
+```
+$ nix-env -i alex
+error: selector ‘alex’ matches no derivations
+$ nix-env -qa ghc
+ghc-7.10.2
+```
+
+The Haskell package set is not registered in the top-level namespace because it
+is *huge*. If all Haskell packages were visible to these commands, then
+name-based search/install operations would be much slower than they are now. We
+avoided that by keeping all Haskell-related packages in a separate attribute
+set called `haskellPackages`, which the following command will list:
+```
+$ nix-env -f "<nixpkgs>" -qaP -A haskellPackages
+haskellPackages.a50         a50-0.5
+haskellPackages.abacate     haskell-abacate-0.0.0.0
+haskellPackages.abcBridge   haskell-abcBridge-0.12
+haskellPackages.afv         afv-0.1.1
+haskellPackages.alex        alex-3.1.4
+haskellPackages.Allure      Allure-0.4.101.1
+haskellPackages.alms        alms-0.6.7
+[... some 8000 entries omitted  ...]
+```
+
+To install any of those packages into your profile, refer to them by their
+attribute path (first column):
+```shell
+nix-env -f "<nixpkgs>" -iA haskellPackages.Allure ...
+```
+
+The attribute path of any Haskell packages corresponds to the name of that
+particular package on Hackage: the package `cabal-install` has the attribute
+`haskellPackages.cabal-install`, and so on. (Actually, this convention causes
+trouble with packages like `3dmodels` and `4Blocks`, because these names are
+invalid identifiers in the Nix language. The issue of how to deal with these
+rare corner cases is currently unresolved.)
+
+Haskell packages whose Nix name (second column) begins with a `haskell-` prefix
+are packages that provide a library whereas packages without that prefix
+provide just executables. Libraries may provide executables too, though: the
+package `haskell-pandoc`, for example, installs both a library and an
+application. You can install and use Haskell executables just like any other
+program in Nixpkgs, but using Haskell libraries for development is a bit
+trickier and we'll address that subject in great detail in section [How to
+create a development environment].
+
+Attribute paths are deterministic inside of Nixpkgs, but the path necessary to
+reach Nixpkgs varies from system to system. We dodged that problem by giving
+`nix-env` an explicit `-f "<nixpkgs>"` parameter, but if you call `nix-env`
+without that flag, then chances are the invocation fails:
+```
+$ nix-env -iA haskellPackages.cabal-install
+error: attribute ‘haskellPackages’ in selection path
+       ‘haskellPackages.cabal-install’ not found
+```
+
+On NixOS, for example, Nixpkgs does *not* exist in the top-level namespace by
+default. To figure out the proper attribute path, it's easiest to query for the
+path of a well-known Nixpkgs package, i.e.:
+```
+$ nix-env -qaP coreutils
+nixos.coreutils  coreutils-8.23
+```
+
+If your system responds like that (most NixOS installations will), then the
+attribute path to `haskellPackages` is `nixos.haskellPackages`. Thus, if you
+want to use `nix-env` without giving an explicit `-f` flag, then that's the way
+to do it:
+```shell
+nix-env -qaP -A nixos.haskellPackages
+nix-env -iA nixos.haskellPackages.cabal-install
+```
+
+Our current default compiler is GHC 7.10.x and the `haskellPackages` set
+contains packages built with that particular version. Nixpkgs contains the
+latest major release of every GHC since 6.10.4, however, and there is a whole
+family of package sets available that defines Hackage packages built with each
+of those compilers, too:
+```shell
+nix-env -f "<nixpkgs>" -qaP -A haskell.packages.ghc6123
+nix-env -f "<nixpkgs>" -qaP -A haskell.packages.ghc763
+```
+
+The name `haskellPackages` is really just a synonym for
+`haskell.packages.ghc7102`, because we prefer that package set internally and
+recommend it to our users as their default choice, but ultimately you are free
+to compile your Haskell packages with any GHC version you please. The following
+command displays the complete list of available compilers:
+```
+$ nix-env -f "<nixpkgs>" -qaP -A haskell.compiler
+haskell.compiler.ghc6104        ghc-6.10.4
+haskell.compiler.ghc6123        ghc-6.12.3
+haskell.compiler.ghc704         ghc-7.0.4
+haskell.compiler.ghc722         ghc-7.2.2
+haskell.compiler.ghc742         ghc-7.4.2
+haskell.compiler.ghc763         ghc-7.6.3
+haskell.compiler.ghc784         ghc-7.8.4
+haskell.compiler.ghc7102        ghc-7.10.2
+haskell.compiler.ghcHEAD        ghc-7.11.20150402
+haskell.compiler.ghcNokinds     ghc-nokinds-7.11.20150704
+haskell.compiler.ghcjs          ghcjs-0.1.0
+haskell.compiler.jhc            jhc-0.8.2
+haskell.compiler.uhc            uhc-1.1.9.0
+```
+
+We have no package sets for `jhc` or `uhc` yet, unfortunately, but for every
+version of GHC listed above, there exists a package set based on that compiler.
+Also, the attributes `haskell.compiler.ghcXYC` and
+`haskell.packages.ghcXYC.ghc` are synonymous for the sake of convenience.
+
+## How to create a development environment
+
+### How to install a compiler
+
+A simple development environment consists of a Haskell compiler and one or both
+of the tools `cabal-install` and `stack`. We saw in section
+[How to install Haskell packages] how you can install those programs into your
+user profile:
+```shell
+nix-env -f "<nixpkgs>" -iA haskellPackages.ghc haskellPackages.cabal-install
+```
+
+Instead of the default package set `haskellPackages`, you can also use the more
+precise name `haskell.compiler.ghc7102`, which has the advantage that it refers
+to the same GHC version regardless of what Nixpkgs considers "default" at any
+given time.
+
+Once you've made those tools available in `$PATH`, it's possible to build
+Hackage packages the same way people without access to Nix do it all the time:
+```shell
+cabal get lens-4.11 && cd lens-4.11
+cabal install -j --dependencies-only
+cabal configure
+cabal build
+```
+
+If you enjoy working with Cabal sandboxes, then that's entirely possible too:
+just execute the command
+```shell
+cabal sandbox init
+```
+before installing the required dependencies.
+
+The `nix-shell` utility makes it easy to switch to a different compiler
+version; just enter the Nix shell environment with the command
+```shell
+nix-shell -p haskell.compiler.ghc784
+```
+to bring GHC 7.8.4 into `$PATH`. Alternatively, you can use Stack instead of
+`nix-shell` directly to select compiler versions and other build tools
+per-project. It uses `nix-shell` under the hood when Nix support is turned on.
+See [How to build a Haskell project using Stack].
+
+If you're using `cabal-install`, re-running `cabal configure` inside the spawned
+shell switches your build to use that compiler instead. If you're working on
+a project that doesn't depend on any additional system libraries outside of GHC,
+then it's even sufficient to just run the `cabal configure` command inside of
+the shell:
+```shell
+nix-shell -p haskell.compiler.ghc784 --command "cabal configure"
+```
+
+Afterwards, all other commands like `cabal build` work just fine in any shell
+environment, because the configure phase recorded the absolute paths to all
+required tools like GHC in its build configuration inside of the `dist/`
+directory. Please note, however, that `nix-collect-garbage` can break such an
+environment because the Nix store paths created by `nix-shell` aren't "alive"
+anymore once `nix-shell` has terminated. If you find that your Haskell builds
+no longer work after garbage collection, then you'll have to re-run `cabal
+configure` inside of a new `nix-shell` environment.
+
+### How to install a compiler with libraries
+
+GHC expects to find all installed libraries inside of its own `lib` directory.
+This approach works fine on traditional Unix systems, but it doesn't work for
+Nix, because GHC's store path is immutable once it's built. We cannot install
+additional libraries into that location. As a consequence, our copies of GHC
+don't know any packages except their own core libraries, like `base`,
+`containers`, `Cabal`, etc.
+
+We can register additional libraries to GHC, however, using a special build
+function called `ghcWithPackages`. That function expects one argument: a
+function that maps from an attribute set of Haskell packages to a list of
+packages, which determines the libraries known to that particular version of
+GHC. For example, the Nix expression `ghcWithPackages (pkgs: [pkgs.mtl])`
+generates a copy of GHC that has the `mtl` library registered in addition to
+its normal core packages:
+```
+$ nix-shell -p "haskellPackages.ghcWithPackages (pkgs: [pkgs.mtl])"
+
+[nix-shell:~]$ ghc-pkg list mtl
+/nix/store/zy79...-ghc-7.10.2/lib/ghc-7.10.2/package.conf.d:
+    mtl-2.2.1
+```
+
+This function allows users to define their own development environment by means
+of an override. After adding the following snippet to `~/.config/nixpkgs/config.nix`,
+```nix
+{
+  packageOverrides = super: let self = super.pkgs; in
+  {
+    myHaskellEnv = self.haskell.packages.ghc7102.ghcWithPackages
+                     (haskellPackages: with haskellPackages; [
+                       # libraries
+                       arrows async cgi criterion
+                       # tools
+                       cabal-install haskintex
+                     ]);
+  };
+}
+```
+it's possible to install that compiler with `nix-env -f "<nixpkgs>" -iA
+myHaskellEnv`. If you'd like to switch that development environment to a
+different version of GHC, just replace the `ghc7102` bit in the previous
+definition with the appropriate name. Of course, it's also possible to define
+any number of these development environments! (You can't install two of them
+into the same profile at the same time, though, because that would result in
+file conflicts.)
+
+The generated `ghc` program is a wrapper script that re-directs the real
+GHC executable to use a new `lib` directory --- one that we specifically
+constructed to contain all those packages the user requested:
+```
+$ cat $(type -p ghc)
+#! /nix/store/xlxj...-bash-4.3-p33/bin/bash -e
+export NIX_GHC=/nix/store/19sm...-ghc-7.10.2/bin/ghc
+export NIX_GHCPKG=/nix/store/19sm...-ghc-7.10.2/bin/ghc-pkg
+export NIX_GHC_DOCDIR=/nix/store/19sm...-ghc-7.10.2/share/doc/ghc/html
+export NIX_GHC_LIBDIR=/nix/store/19sm...-ghc-7.10.2/lib/ghc-7.10.2
+exec /nix/store/j50p...-ghc-7.10.2/bin/ghc "-B$NIX_GHC_LIBDIR" "$@"
+```
+
+The variables `$NIX_GHC`, `$NIX_GHCPKG`, etc. point to the *new* store path
+`ghcWithPackages` constructed specifically for this environment. The last line
+of the wrapper script then executes the real `ghc`, but passes the path to the
+new `lib` directory using GHC's `-B` flag.
+
+The purpose of those environment variables is to work around an impurity in the
+popular [ghc-paths](http://hackage.haskell.org/package/ghc-paths) library. That
+library promises to give its users access to GHC's installation paths. Only,
+the library can't possible know that path when it's compiled, because the path
+GHC considers its own is determined only much later, when the user configures
+it through `ghcWithPackages`. So we [patched
+ghc-paths](https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/haskell-modules/patches/ghc-paths-nix.patch)
+to return the paths found in those environment variables at run-time rather
+than trying to guess them at compile-time.
+
+To make sure that mechanism works properly all the time, we recommend that you
+set those variables to meaningful values in your shell environment, too, i.e.
+by adding the following code to your `~/.bashrc`:
+```bash
+if type >/dev/null 2>&1 -p ghc; then
+  eval "$(egrep ^export "$(type -p ghc)")"
+fi
+```
+
+If you are certain that you'll use only one GHC environment which is located in
+your user profile, then you can use the following code, too, which has the
+advantage that it doesn't contain any paths from the Nix store, i.e. those
+settings always remain valid even if a `nix-env -u` operation updates the GHC
+environment in your profile:
+```bash
+if [ -e ~/.nix-profile/bin/ghc ]; then
+  export NIX_GHC="$HOME/.nix-profile/bin/ghc"
+  export NIX_GHCPKG="$HOME/.nix-profile/bin/ghc-pkg"
+  export NIX_GHC_DOCDIR="$HOME/.nix-profile/share/doc/ghc/html"
+  export NIX_GHC_LIBDIR="$HOME/.nix-profile/lib/ghc-$($NIX_GHC --numeric-version)"
+fi
+```
+
+### How to install a compiler with libraries, hoogle and documentation indexes
+
+If you plan to use your environment for interactive programming, not just
+compiling random Haskell code, you might want to replace `ghcWithPackages` in
+all the listings above with `ghcWithHoogle`.
+
+This environment generator not only produces an environment with GHC and all
+the specified libraries, but also generates a `hoogle` and `haddock` indexes
+for all the packages, and provides a wrapper script around `hoogle` binary that
+uses all those things. A precise name for this thing would be
+"`ghcWithPackagesAndHoogleAndDocumentationIndexes`", which is, regrettably, too
+long and scary.
+
+For example, installing the following environment
+```nix
+{
+  packageOverrides = super: let self = super.pkgs; in
+  {
+    myHaskellEnv = self.haskellPackages.ghcWithHoogle
+                     (haskellPackages: with haskellPackages; [
+                       # libraries
+                       arrows async cgi criterion
+                       # tools
+                       cabal-install haskintex
+                     ]);
+  };
+}
+```
+allows one to browse module documentation index [not too dissimilar to
+this](https://downloads.haskell.org/~ghc/latest/docs/html/libraries/index.html)
+for all the specified packages and their dependencies by directing a browser of
+choice to `~/.nix-profile/share/doc/hoogle/index.html` (or
+`/run/current-system/sw/share/doc/hoogle/index.html` in case you put it in
+`environment.systemPackages` in NixOS).
+
+After you've marveled enough at that try adding the following to your
+`~/.ghc/ghci.conf`
+```
+:def hoogle \s -> return $ ":! hoogle search -cl --count=15 \"" ++ s ++ "\""
+:def doc \s -> return $ ":! hoogle search -cl --info \"" ++ s ++ "\""
+```
+and test it by typing into `ghci`:
+```
+:hoogle a -> a
+:doc a -> a
+```
+
+Be sure to note the links to `haddock` files in the output. With any modern and
+properly configured terminal emulator you can just click those links to
+navigate there.
+
+Finally, you can run
+```shell
+hoogle server --local -p 8080
+```
+and navigate to http://localhost:8080/ for your own local
+[Hoogle](https://www.haskell.org/hoogle/). The `--local` flag makes the hoogle
+server serve files from your nix store over http, without the flag it will use
+`file://` URIs. Note, however, that Firefox and possibly other browsers
+disallow navigation from `http://` to `file://` URIs for security reasons,
+which might be quite an inconvenience. Versions before v5 did not have this
+flag. See
+[this page](http://kb.mozillazine.org/Links_to_local_pages_do_not_work) for
+workarounds.
+
+For NixOS users there's a service which runs this exact command for you.
+Specify the `packages` you want documentation for and the `haskellPackages` set
+you want them to come from. Add the following to `configuration.nix`.
+
+```nix
+services.hoogle = {
+enable = true;
+packages = (hpkgs: with hpkgs; [text cryptonite]);
+haskellPackages = pkgs.haskellPackages;
+};
+```
+
+### How to build a Haskell project using Stack
+
+[Stack](http://haskellstack.org) is a popular build tool for Haskell projects.
+It has first-class support for Nix. Stack can optionally use Nix to
+automatically select the right version of GHC and other build tools to build,
+test and execute apps in an existing project downloaded from somewhere on the
+Internet. Pass the `--nix` flag to any `stack` command to do so, e.g.
+```shell
+git clone --recursive http://github.com/yesodweb/wai
+cd wai
+stack --nix build
+```
+
+If you want `stack` to use Nix by default, you can add a `nix` section to the
+`stack.yaml` file, as explained in the [Stack documentation][stack-nix-doc]. For
+example:
+```yaml
+nix:
+  enable: true
+  packages: [pkgconfig zeromq zlib]
+```
+
+The example configuration snippet above tells Stack to create an ad hoc
+environment for `nix-shell` as in the below section, in which the `pkgconfig`,
+`zeromq` and `zlib` packages from Nixpkgs are available. All `stack` commands
+will implicitly be executed inside this ad hoc environment.
+
+Some projects have more sophisticated needs. For examples, some ad hoc
+environments might need to expose Nixpkgs packages compiled in a certain way, or
+with extra environment variables. In these cases, you'll need a `shell` field
+instead of `packages`:
+```yaml
+nix:
+  enable: true
+  shell-file: shell.nix
+```
+
+For more on how to write a `shell.nix` file see the below section. You'll need
+to express a derivation. Note that Nixpkgs ships with a convenience wrapper
+function around `mkDerivation` called `haskell.lib.buildStackProject` to help you
+create this derivation in exactly the way Stack expects. All of the same inputs
+as `mkDerivation` can be provided. For example, to build a Stack project that
+including packages that link against a version of the R library compiled with
+special options turned on:
+```nix
+with (import <nixpkgs> { });
+
+let R = pkgs.R.override { enableStrictBarrier = true; };
+in
+haskell.lib.buildStackProject {
+  name = "HaskellR";
+  buildInputs = [ R zeromq zlib ];
+}
+```
+
+You can select a particular GHC version to compile with by setting the
+`ghc` attribute as an argument to `buildStackProject`. Better yet, let
+Stack choose what GHC version it wants based on the snapshot specified
+in `stack.yaml` (only works with Stack >= 1.1.3):
+```nix
+{nixpkgs ? import <nixpkgs> { }, ghc ? nixpkgs.ghc}:
+
+with nixpkgs;
+
+let R = pkgs.R.override { enableStrictBarrier = true; };
+in
+haskell.lib.buildStackProject {
+  name = "HaskellR";
+  buildInputs = [ R zeromq zlib ];
+  inherit ghc;
+}
+```
+
+[stack-nix-doc]: http://docs.haskellstack.org/en/stable/nix_integration.html
+
+### How to create ad hoc environments for `nix-shell`
+
+The easiest way to create an ad hoc development environment is to run
+`nix-shell` with the appropriate GHC environment given on the command-line:
+```shell
+nix-shell -p "haskellPackages.ghcWithPackages (pkgs: with pkgs; [mtl pandoc])"
+```
+
+For more sophisticated use-cases, however, it's more convenient to save the
+desired configuration in a file called `shell.nix` that looks like this:
+```nix
+{ nixpkgs ? import <nixpkgs> {}, compiler ? "ghc7102" }:
+let
+  inherit (nixpkgs) pkgs;
+  ghc = pkgs.haskell.packages.${compiler}.ghcWithPackages (ps: with ps; [
+          monad-par mtl
+        ]);
+in
+pkgs.stdenv.mkDerivation {
+  name = "my-haskell-env-0";
+  buildInputs = [ ghc ];
+  shellHook = "eval $(egrep ^export ${ghc}/bin/ghc)";
+}
+```
+
+Now run `nix-shell` --- or even `nix-shell --pure` --- to enter a shell
+environment that has the appropriate compiler in `$PATH`. If you use `--pure`,
+then add all other packages that your development environment needs into the
+`buildInputs` attribute. If you'd like to switch to a different compiler
+version, then pass an appropriate `compiler` argument to the expression, i.e.
+`nix-shell --argstr compiler ghc784`.
+
+If you need such an environment because you'd like to compile a Hackage package
+outside of Nix --- i.e. because you're hacking on the latest version from Git
+---, then the package set provides suitable nix-shell environments for you
+already! Every Haskell package has an `env` attribute that provides a shell
+environment suitable for compiling that particular package. If you'd like to
+hack the `lens` library, for example, then you just have to check out the
+source code and enter the appropriate environment:
+```
+$ cabal get lens-4.11 && cd lens-4.11
+Downloading lens-4.11...
+Unpacking to lens-4.11/
+
+$ nix-shell "<nixpkgs>" -A haskellPackages.lens.env
+[nix-shell:/tmp/lens-4.11]$
+```
+
+At point, you can run `cabal configure`, `cabal build`, and all the other
+development commands. Note that you need `cabal-install` installed in your
+`$PATH` already to use it here --- the `nix-shell` environment does not provide
+it.
+
+## How to create Nix builds for your own private Haskell packages
+
+If your own Haskell packages have build instructions for Cabal, then you can
+convert those automatically into build instructions for Nix using the
+`cabal2nix` utility, which you can install into your profile by running
+`nix-env -i cabal2nix`.
+
+### How to build a stand-alone project
+
+For example, let's assume that you're working on a private project called
+`foo`. To generate a Nix build expression for it, change into the project's
+top-level directory and run the command:
+```shell
+cabal2nix . > foo.nix
+```
+Then write the following snippet into a file called `default.nix`:
+```nix
+{ nixpkgs ? import <nixpkgs> {}, compiler ? "ghc7102" }:
+nixpkgs.pkgs.haskell.packages.${compiler}.callPackage ./foo.nix { }
+```
+
+Finally, store the following code in a file called `shell.nix`:
+```nix
+{ nixpkgs ? import <nixpkgs> {}, compiler ? "ghc7102" }:
+(import ./default.nix { inherit nixpkgs compiler; }).env
+```
+
+At this point, you can run `nix-build` to have Nix compile your project and
+install it into a Nix store path. The local directory will contain a symlink
+called `result` after `nix-build` returns that points into that location. Of
+course, passing the flag `--argstr compiler ghc763` allows switching the build
+to any version of GHC currently supported.
+
+Furthermore, you can call `nix-shell` to enter an interactive development
+environment in which you can use `cabal configure` and `cabal build` to develop
+your code. That environment will automatically contain a proper GHC derivation
+with all the required libraries registered as well as all the system-level
+libraries your package might need.
+
+If your package does not depend on any system-level libraries, then it's
+sufficient to run
+```shell
+nix-shell --command "cabal configure"
+```
+once to set up your build. `cabal-install` determines the absolute paths to all
+resources required for the build and writes them into a config file in the
+`dist/` directory. Once that's done, you can run `cabal build` and any other
+command for that project even outside of the `nix-shell` environment. This
+feature is particularly nice for those of us who like to edit their code with
+an IDE, like Emacs' `haskell-mode`, because it's not necessary to start Emacs
+inside of nix-shell just to make it find out the necessary settings for
+building the project; `cabal-install` has already done that for us.
+
+If you want to do some quick-and-dirty hacking and don't want to bother setting
+up a `default.nix` and `shell.nix` file manually, then you can use the
+`--shell` flag offered by `cabal2nix` to have it generate a stand-alone
+`nix-shell` environment for you. With that feature, running
+```shell
+cabal2nix --shell . > shell.nix
+nix-shell --command "cabal configure"
+```
+is usually enough to set up a build environment for any given Haskell package.
+You can even use that generated file to run `nix-build`, too:
+```shell
+nix-build shell.nix
+```
+
+### How to build projects that depend on each other
+
+If you have multiple private Haskell packages that depend on each other, then
+you'll have to register those packages in the Nixpkgs set to make them visible
+for the dependency resolution performed by `callPackage`. First of all, change
+into each of your projects top-level directories and generate a `default.nix`
+file with `cabal2nix`:
+```shell
+cd ~/src/foo && cabal2nix . > default.nix
+cd ~/src/bar && cabal2nix . > default.nix
+```
+Then edit your `~/.config/nixpkgs/config.nix` file to register those builds in the
+default Haskell package set:
+```nix
+{
+  packageOverrides = super: let self = super.pkgs; in
+  {
+    haskellPackages = super.haskellPackages.override {
+      overrides = self: super: {
+        foo = self.callPackage ../src/foo {};
+        bar = self.callPackage ../src/bar {};
+      };
+    };
+  };
+}
+```
+Once that's accomplished, `nix-env -f "<nixpkgs>" -qA haskellPackages` will
+show your packages like any other package from Hackage, and you can build them
+```shell
+nix-build "<nixpkgs>" -A haskellPackages.foo
+```
+or enter an interactive shell environment suitable for building them:
+```shell
+nix-shell "<nixpkgs>" -A haskellPackages.bar.env
+```
+
+## Miscellaneous Topics
+
+### How to build with profiling enabled
+
+Every Haskell package set takes a function called `overrides` that you can use
+to manipulate the package as much as you please. One useful application of this
+feature is to replace the default `mkDerivation` function with one that enables
+library profiling for all packages. To accomplish that add the following
+snippet to your `~/.config/nixpkgs/config.nix` file:
+```nix
+{
+  packageOverrides = super: let self = super.pkgs; in
+  {
+    profiledHaskellPackages = self.haskellPackages.override {
+      overrides = self: super: {
+        mkDerivation = args: super.mkDerivation (args // {
+          enableLibraryProfiling = true;
+        });
+      };
+    };
+  };
+}
+```
+Then, replace instances of `haskellPackages` in the `cabal2nix`-generated
+`default.nix` or `shell.nix` files with `profiledHaskellPackages`.
+
+### How to override package versions in a compiler-specific package set
+
+Nixpkgs provides the latest version of
+[`ghc-events`](http://hackage.haskell.org/package/ghc-events), which is 0.4.4.0
+at the time of this writing. This is fine for users of GHC 7.10.x, but GHC
+7.8.4 cannot compile that binary. Now, one way to solve that problem is to
+register an older version of `ghc-events` in the 7.8.x-specific package set.
+The first step is to generate Nix build instructions with `cabal2nix`:
+```shell
+cabal2nix cabal://ghc-events-0.4.3.0 > ~/.nixpkgs/ghc-events-0.4.3.0.nix
+```
+Then add the override in `~/.config/nixpkgs/config.nix`:
+```nix
+{
+  packageOverrides = super: let self = super.pkgs; in
+  {
+    haskell = super.haskell // {
+      packages = super.haskell.packages // {
+        ghc784 = super.haskell.packages.ghc784.override {
+          overrides = self: super: {
+            ghc-events = self.callPackage ./ghc-events-0.4.3.0.nix {};
+          };
+        };
+      };
+    };
+  };
+}
+```
+
+This code is a little crazy, no doubt, but it's necessary because the intuitive
+version
+```nix
+{ # ...
+
+  haskell.packages.ghc784 = super.haskell.packages.ghc784.override {
+    overrides = self: super: {
+      ghc-events = self.callPackage ./ghc-events-0.4.3.0.nix {};
+    };
+  };
+}
+```
+doesn't do what we want it to: that code replaces the `haskell` package set in
+Nixpkgs with one that contains only one entry,`packages`, which contains only
+one entry `ghc784`. This override loses the `haskell.compiler` set, and it
+loses the `haskell.packages.ghcXYZ` sets for all compilers but GHC 7.8.4. To
+avoid that problem, we have to perform the convoluted little dance from above,
+iterating over each step in hierarchy.
+
+Once it's accomplished, however, we can install a variant of `ghc-events`
+that's compiled with GHC 7.8.4:
+```shell
+nix-env -f "<nixpkgs>" -iA haskell.packages.ghc784.ghc-events
+```
+Unfortunately, it turns out that this build fails again while executing the
+test suite! Apparently, the release archive on Hackage is missing some data
+files that the test suite requires, so we cannot run it. We accomplish that by
+re-generating the Nix expression with the `--no-check` flag:
+```shell
+cabal2nix --no-check cabal://ghc-events-0.4.3.0 > ~/.nixpkgs/ghc-events-0.4.3.0.nix
+```
+Now the builds succeeds.
+
+Of course, in the concrete example of `ghc-events` this whole exercise is not
+an ideal solution, because `ghc-events` can analyze the output emitted by any
+version of GHC later than 6.12 regardless of the compiler version that was used
+to build the `ghc-events` executable, so strictly speaking there's no reason to
+prefer one built with GHC 7.8.x in the first place. However, for users who
+cannot use GHC 7.10.x at all for some reason, the approach of downgrading to an
+older version might be useful.
+
+### How to override packages in all compiler-specific package sets
+
+In the previous section we learned how to override a package in a single
+compiler-specific package set. You may have some overrides defined that you want
+to use across multiple package sets. To accomplish this you could use the
+technique that we learned in the previous section by repeating the overrides for
+all the compiler-specific package sets. For example:
+
+```nix
+{
+  packageOverrides = super: let self = super.pkgs; in
+  {
+    haskell = super.haskell // {
+      packages = super.haskell.packages // {
+        ghc784 = super.haskell.packages.ghc784.override {
+          overrides = self: super: {
+            my-package = ...;
+            my-other-package = ...;
+          };
+        };
+        ghc822 = super.haskell.packages.ghc784.override {
+          overrides = self: super: {
+            my-package = ...;
+            my-other-package = ...;
+          };
+        };
+        ...
+      };
+    };
+  };
+}
+```
+
+However there's a more convenient way to override all compiler-specific package
+sets at once:
+
+```nix
+{
+  packageOverrides = super: let self = super.pkgs; in
+  {
+    haskell = super.haskell // {
+      packageOverrides = self: super: {
+        my-package = ...;
+        my-other-package = ...;
+      };
+    };
+  };
+}
+```
+
+### How to specify source overrides for your Haskell package
+
+When starting a Haskell project you can use `developPackage`
+to define a derivation for your package at the `root` path
+as well as source override versions for Hackage packages, like so:
+
+```nix
+# default.nix
+{ compilerVersion ? "ghc842" }:
+let
+  # pinning nixpkgs using new Nix 2.0 builtin `fetchGit`
+  pkgs = import (fetchGit (import ./version.nix)) { };
+  compiler = pkgs.haskell.packages."${compilerVersion}";
+  pkg = compiler.developPackage {
+    root = ./.;
+    source-overrides = {
+      # Let's say the GHC 8.4.2 haskellPackages uses 1.6.0.0 and your test suite is incompatible with >= 1.6.0.0
+      HUnit = "1.5.0.0";
+    };
+  };
+in pkg
+```
+
+This could be used in place of a simplified `stack.yaml` defining a Nix
+derivation for your Haskell package.
+
+As you can see this allows you to specify only the source version found on
+Hackage and nixpkgs will take care of the rest.
+
+You can also specify `buildInputs` for your Haskell derivation for packages
+that directly depend on external libraries like so:
+
+```nix
+# default.nix
+{ compilerVersion ? "ghc842" }:
+let
+  # pinning nixpkgs using new Nix 2.0 builtin `fetchGit`
+  pkgs = import (fetchGit (import ./version.nix)) { };
+  compiler = pkgs.haskell.packages."${compilerVersion}";
+  pkg = compiler.developPackage {
+    root = ./.;
+    source-overrides = {
+      HUnit = "1.5.0.0"; # Let's say the GHC 8.4.2 haskellPackages uses 1.6.0.0 and your test suite is incompatible with >= 1.6.0.0
+    };
+  };
+  # in case your package source depends on any libraries directly, not just transitively.
+  buildInputs = [ zlib ];
+in pkg.overrideAttrs(attrs: {
+  buildInputs = attrs.buildInputs ++ buildInputs;
+})
+```
+
+Notice that you will need to override (via `overrideAttrs` or similar) the
+derivation returned by the `developPackage` Nix lambda as there is no `buildInputs`
+named argument you can pass directly into the `developPackage` lambda.
+
+### How to recover from GHC's infamous non-deterministic library ID bug
+
+GHC and distributed build farms don't get along well:
+
+  - https://ghc.haskell.org/trac/ghc/ticket/4012
+
+When you see an error like this one
+```
+package foo-0.7.1.0 is broken due to missing package
+text-1.2.0.4-98506efb1b9ada233bb5c2b2db516d91
+```
+then you have to download and re-install `foo` and all its dependents from
+scratch:
+```shell
+nix-store -q --referrers /nix/store/*-haskell-text-1.2.0.4 \
+  | xargs -L 1 nix-store --repair-path
+```
+
+If you're using additional Hydra servers other than `hydra.nixos.org`, then it
+might be necessary to purge the local caches that store data from those
+machines to disable these binary channels for the duration of the previous
+command, i.e. by running:
+```shell
+rm ~/.cache/nix/binary-cache*.sqlite
+```
+
+### Builds on Darwin fail with `math.h` not found
+
+Users of GHC on Darwin have occasionally reported that builds fail, because the
+compiler complains about a missing include file:
+```
+fatal error: 'math.h' file not found
+```
+The issue has been discussed at length in [ticket
+6390](https://github.com/NixOS/nixpkgs/issues/6390), and so far no good
+solution has been proposed. As a work-around, users who run into this problem
+can configure the environment variables
+```shell
+export NIX_CFLAGS_COMPILE="-idirafter /usr/include"
+export NIX_CFLAGS_LINK="-L/usr/lib"
+```
+in their `~/.bashrc` file to avoid the compiler error.
+
+### Builds using Stack complain about missing system libraries
+
+```
+--  While building package zlib-0.5.4.2 using:
+  runhaskell -package=Cabal-1.22.4.0 -clear-package-db [... lots of flags ...]
+Process exited with code: ExitFailure 1
+Logs have been written to: /home/foo/src/stack-ide/.stack-work/logs/zlib-0.5.4.2.log
+
+Configuring zlib-0.5.4.2...
+Setup.hs: Missing dependency on a foreign library:
+* Missing (or bad) header file: zlib.h
+This problem can usually be solved by installing the system package that
+provides this library (you may need the "-dev" version). If the library is
+already installed but in a non-standard location then you can use the flags
+--extra-include-dirs= and --extra-lib-dirs= to specify where it is.
+If the header file does exist, it may contain errors that are caught by the C
+compiler at the preprocessing stage. In this case you can re-run configure
+with the verbosity flag -v3 to see the error messages.
+```
+
+When you run the build inside of the nix-shell environment, the system
+is configured to find `libz.so` without any special flags -- the compiler
+and linker "just know" how to find it. Consequently, Cabal won't record
+any search paths for `libz.so` in the package description, which means
+that the package works fine inside of nix-shell, but once you leave the
+shell the shared object can no longer be found. That issue is by no
+means specific to Stack: you'll have that problem with any other
+Haskell package that's built inside of nix-shell but run outside of that
+environment.
+
+You can remedy this issue in several ways. The easiest is to add a `nix` section
+to the `stack.yaml` like the following:
+```yaml
+nix:
+  enable: true
+  packages: [ zlib ]
+```
+
+Stack's Nix support knows to add `${zlib.out}/lib` and `${zlib.dev}/include`
+as an `--extra-lib-dirs` and `extra-include-dirs`, respectively.
+Alternatively, you can achieve the same effect by hand. First of all, run
+```
+$ nix-build --no-out-link "<nixpkgs>" -A zlib
+/nix/store/alsvwzkiw4b7ip38l4nlfjijdvg3fvzn-zlib-1.2.8
+```
+to find out the store path of the system's zlib library. Now, you can
+
+  1. add that path (plus a "/lib" suffix) to your `$LD_LIBRARY_PATH`
+    environment variable to make sure your system linker finds `libz.so`
+    automatically. It's no pretty solution, but it will work.
+
+  2. As a variant of (1), you can also install any number of system
+    libraries into your user's profile (or some other profile) and point
+    `$LD_LIBRARY_PATH` to that profile instead, so that you don't have to
+    list dozens of those store paths all over the place.
+
+  3. The solution I prefer is to call stack with an appropriate
+    --extra-lib-dirs flag like so:
+    ```shell
+    stack --extra-lib-dirs=/nix/store/alsvwzkiw4b7ip38l4nlfjijdvg3fvzn-zlib-1.2.8/lib build
+    ```
+
+Typically, you'll need `--extra-include-dirs` as well. It's possible
+to add those flag to the project's `stack.yaml` or your user's
+global `~/.stack/global/stack.yaml` file so that you don't have to
+specify them manually every time. But again, you're likely better off
+using Stack's Nix support instead.
+
+The same thing applies to `cabal configure`, of course, if you're
+building with `cabal-install` instead of Stack.
+
+### Creating statically linked binaries
+
+There are two levels of static linking. The first option is to configure the
+build with the Cabal flag `--disable-executable-dynamic`. In Nix expressions,
+this can be achieved by setting the attribute:
+```
+enableSharedExecutables = false;
+```
+That gives you a binary with statically linked Haskell libraries and
+dynamically linked system libraries.
+
+To link both Haskell libraries and system libraries statically, the additional
+flags `--ghc-option=-optl=-static --ghc-option=-optl=-pthread` need to be used.
+In Nix, this is accomplished with:
+```
+configureFlags = [ "--ghc-option=-optl=-static" "--ghc-option=-optl=-pthread" ];
+```
+
+It's important to realize, however, that most system libraries in Nix are
+built as shared libraries only, i.e. there is just no static library
+available that Cabal could link!
+
+### Building GHC with integer-simple
+
+By default GHC implements the Integer type using the
+[GNU Multiple Precision Arithmetic (GMP) library](https://gmplib.org/).
+The implementation can be found in the
+[integer-gmp](http://hackage.haskell.org/package/integer-gmp) package.
+
+A potential problem with this is that GMP is licensed under the
+[GNU Lesser General Public License (LGPL)](https://www.gnu.org/copyleft/lesser.html),
+a kind of "copyleft" license. According to the terms of the LGPL, paragraph 5,
+you may distribute a program that is designed to be compiled and dynamically
+linked with the library under the terms of your choice (i.e., commercially) but
+if your program incorporates portions of the library, if it is linked
+statically, then your program is a "derivative"--a "work based on the
+library"--and according to paragraph 2, section c, you "must cause the whole of
+the work to be licensed" under the terms of the LGPL (including for free).
+
+The LGPL licensing for GMP is a problem for the overall licensing of binary
+programs compiled with GHC because most distributions (and builds) of GHC use
+static libraries. (Dynamic libraries are currently distributed only for macOS.)
+The LGPL licensing situation may be worse: even though
+[The Glasgow Haskell Compiler License](https://www.haskell.org/ghc/license)
+is essentially a "free software" license (BSD3), according to
+paragraph 2 of the LGPL, GHC must be distributed under the terms of the LGPL!
+
+To work around these problems GHC can be build with a slower but LGPL-free
+alternative implemention for Integer called
+[integer-simple](http://hackage.haskell.org/package/integer-simple).
+
+To get a GHC compiler build with `integer-simple` instead of `integer-gmp` use
+the attribute: `haskell.compiler.integer-simple."${ghcVersion}"`.
+For example:
+```
+$ nix-build -E '(import <nixpkgs> {}).haskell.compiler.integer-simple.ghc802'
+...
+$ result/bin/ghc-pkg list | grep integer
+    integer-simple-0.1.1.1
+```
+The following command displays the complete list of GHC compilers build with `integer-simple`:
+```
+$ nix-env -f "<nixpkgs>" -qaP -A haskell.compiler.integer-simple
+haskell.compiler.integer-simple.ghc7102  ghc-7.10.2
+haskell.compiler.integer-simple.ghc7103  ghc-7.10.3
+haskell.compiler.integer-simple.ghc722   ghc-7.2.2
+haskell.compiler.integer-simple.ghc742   ghc-7.4.2
+haskell.compiler.integer-simple.ghc783   ghc-7.8.3
+haskell.compiler.integer-simple.ghc784   ghc-7.8.4
+haskell.compiler.integer-simple.ghc801   ghc-8.0.1
+haskell.compiler.integer-simple.ghc802   ghc-8.0.2
+haskell.compiler.integer-simple.ghcHEAD  ghc-8.1.20170106
+```
+
+To get a package set supporting `integer-simple` use the attribute:
+`haskell.packages.integer-simple."${ghcVersion}"`. For example
+use the following to get the `scientific` package build with `integer-simple`:
+```shell
+nix-build -A haskell.packages.integer-simple.ghc802.scientific
+```
+
+### Quality assurance
+
+The `haskell.lib` library includes a number of functions for checking for
+various imperfections in Haskell packages. It's useful to apply these functions
+to your own Haskell packages and integrate that in a Continuous Integration
+server like [hydra](https://nixos.org/hydra/) to assure your packages maintain a
+minimum level of quality. This section discusses some of these functions.
+
+#### failOnAllWarnings
+
+Applying `haskell.lib.failOnAllWarnings` to a Haskell package enables the
+`-Wall` and `-Werror` GHC options to turn all warnings into build failures.
+
+#### buildStrictly
+
+Applying `haskell.lib.buildStrictly` to a Haskell package calls
+`failOnAllWarnings` on the given package to turn all warnings into build
+failures. Additionally the source of your package is gotten from first invoking
+`cabal sdist` to ensure all needed files are listed in the Cabal file.
+
+#### checkUnusedPackages
+
+Applying `haskell.lib.checkUnusedPackages` to a Haskell package invokes
+the [packunused](http://hackage.haskell.org/package/packunused) tool on the
+package. `packunused` complains when it finds packages listed as build-depends
+in the Cabal file which are redundant. For example:
+
+```
+$ nix-build -E 'let pkgs = import <nixpkgs> {}; in pkgs.haskell.lib.checkUnusedPackages {} pkgs.haskellPackages.scientific'
+these derivations will be built:
+  /nix/store/3lc51cxj2j57y3zfpq5i69qbzjpvyci1-scientific-0.3.5.1.drv
+...
+detected package components
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+ - library
+ - testsuite(s): test-scientific
+ - benchmark(s): bench-scientific*
+
+(component names suffixed with '*' are not configured to be built)
+
+library
+~~~~~~~
+
+The following package dependencies seem redundant:
+
+ - ghc-prim-0.5.0.0
+
+testsuite(test-scientific)
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+no redundant packages dependencies found
+
+builder for ‘/nix/store/3lc51cxj2j57y3zfpq5i69qbzjpvyci1-scientific-0.3.5.1.drv’ failed with exit code 1
+error: build of ‘/nix/store/3lc51cxj2j57y3zfpq5i69qbzjpvyci1-scientific-0.3.5.1.drv’ failed
+```
+
+As you can see, `packunused` finds out that although the testsuite component has
+no redundant dependencies the library component of `scientific-0.3.5.1` depends
+on `ghc-prim` which is unused in the library.
+
+### Using hackage2nix with nixpkgs
+
+Hackage package derivations are found in the
+[`hackage-packages.nix`](https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/haskell-modules/hackage-packages.nix)
+file within `nixpkgs` and are used as the initial package set for
+`haskellPackages`. The `hackage-packages.nix` file is not meant to be edited
+by hand, but rather autogenerated by [`hackage2nix`](https://github.com/NixOS/cabal2nix/tree/master/hackage2nix),
+which by default uses the [`configuration-hackage2nix.yaml`](https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/haskell-modules/configuration-hackage2nix.yaml)
+file to generate all the derivations.
+
+To modify the contents `configuration-hackage2nix.yaml`, follow the
+instructions on [`hackage2nix`](https://github.com/NixOS/cabal2nix/tree/master/hackage2nix).
+
+## Other resources
+
+  - The Youtube video [Nix Loves Haskell](https://www.youtube.com/watch?v=BsBhi_r-OeE)
+    provides an introduction into Haskell NG aimed at beginners. The slides are
+    available at http://cryp.to/nixos-meetup-3-slides.pdf and also -- in a form
+    ready for cut & paste -- at
+    https://github.com/NixOS/cabal2nix/blob/master/doc/nixos-meetup-3-slides.md.
+
+  - Another Youtube video is [Escaping Cabal Hell with Nix](https://www.youtube.com/watch?v=mQd3s57n_2Y),
+    which discusses the subject of Haskell development with Nix but also provides
+    a basic introduction to Nix as well, i.e. it's suitable for viewers with
+    almost no prior Nix experience.
+
+  - Oliver Charles wrote a very nice [Tutorial how to develop Haskell packages with Nix](http://wiki.ocharles.org.uk/Nix).
+
+  - The *Journey into the Haskell NG infrastructure* series of postings
+    describe the new Haskell infrastructure in great detail:
+
+      - [Part 1](https://nixos.org/nix-dev/2015-January/015591.html)
+        explains the differences between the old and the new code and gives
+        instructions how to migrate to the new setup.
+
+      - [Part 2](https://nixos.org/nix-dev/2015-January/015608.html)
+        looks in-depth at how to tweak and configure your setup by means of
+        overrides.
+
+      - [Part 3](https://nixos.org/nix-dev/2015-April/016912.html)
+        describes the infrastructure that keeps the Haskell package set in Nixpkgs
+        up-to-date.
diff --git a/nixpkgs/doc/languages-frameworks/idris.section.md b/nixpkgs/doc/languages-frameworks/idris.section.md
new file mode 100644
index 000000000000..50979d76d98b
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/idris.section.md
@@ -0,0 +1,115 @@
+# Idris packages
+
+## Installing Idris
+
+The easiest way to get a working idris version is to install the `idris` attribute:
+
+```
+$ # On NixOS
+$ nix-env -i nixos.idris
+$ # On non-NixOS
+$ nix-env -i nixpkgs.idris
+```
+
+This however only provides the `prelude` and `base` libraries. To install additional libraries:
+
+```
+$ nix-env -iE 'pkgs: pkgs.idrisPackages.with-packages (with pkgs.idrisPackages; [ contrib pruviloj ])'
+```
+
+To see all available Idris packages:
+```
+$ # On NixOS
+$ nix-env -qaPA nixos.idrisPackages
+$ # On non-NixOS
+$ nix-env -qaPA nixpkgs.idrisPackages
+```
+
+Similarly, entering a `nix-shell`:
+```
+$ nix-shell -p 'idrisPackages.with-packages (with idrisPackages; [ contrib pruviloj ])'
+```
+
+## Starting Idris with library support
+
+To have access to these libraries in idris, call it with an argument `-p <library name>` for each library:
+
+```
+$ nix-shell -p 'idrisPackages.with-packages (with idrisPackages; [ contrib pruviloj ])'
+[nix-shell:~]$ idris -p contrib -p pruviloj
+```
+
+A listing of all available packages the Idris binary has access to is available via `--listlibs`:
+
+```
+$ idris --listlibs
+00prelude-idx.ibc
+pruviloj
+base
+contrib
+prelude
+00pruviloj-idx.ibc
+00base-idx.ibc
+00contrib-idx.ibc
+```
+
+## Building an Idris project with Nix
+
+As an example of how a Nix expression for an Idris package can be created, here is the one for `idrisPackages.yaml`:
+
+```nix
+{ build-idris-package
+, fetchFromGitHub
+, contrib
+, lightyear
+, lib
+}:
+build-idris-package  {
+  name = "yaml";
+  version = "2018-01-25";
+
+  # This is the .ipkg file that should be built, defaults to the package name
+  # In this case it should build `Yaml.ipkg` instead of `yaml.ipkg`
+  # This is only necessary because the yaml packages ipkg file is
+  # different from its package name here.
+  ipkgName = "Yaml";
+  # Idris dependencies to provide for the build
+  idrisDeps = [ contrib lightyear ];
+
+  src = fetchFromGitHub {
+    owner = "Heather";
+    repo = "Idris.Yaml";
+    rev = "5afa51ffc839844862b8316faba3bafa15656db4";
+    sha256 = "1g4pi0swmg214kndj85hj50ccmckni7piprsxfdzdfhg87s0avw7";
+  };
+
+  meta = {
+    description = "Idris YAML lib";
+    homepage = https://github.com/Heather/Idris.Yaml;
+    license = lib.licenses.mit;
+    maintainers = [ lib.maintainers.brainrape ];
+  };
+}
+```
+
+Assuming this file is saved as `yaml.nix`, it's buildable using
+
+```
+$ nix-build -E '(import <nixpkgs> {}).idrisPackages.callPackage ./yaml.nix {}'
+```
+
+Or it's possible to use
+
+```nix
+with import <nixpkgs> {};
+
+{
+  yaml = idrisPackages.callPackage ./yaml.nix {};
+}
+```
+
+in another file (say `default.nix`) to be able to build it with
+
+```
+$ nix-build -A yaml
+```
diff --git a/nixpkgs/doc/languages-frameworks/index.xml b/nixpkgs/doc/languages-frameworks/index.xml
new file mode 100644
index 000000000000..4564df98fe99
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/index.xml
@@ -0,0 +1,35 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xi="http://www.w3.org/2001/XInclude"
+         xml:id="chap-language-support">
+ <title>Support for specific programming languages and frameworks</title>
+ <para>
+  The <link linkend="chap-stdenv">standard build environment</link> makes it
+  easy to build typical Autotools-based packages with very little code. Any
+  other kind of package can be accomodated by overriding the appropriate phases
+  of <literal>stdenv</literal>. However, there are specialised functions in
+  Nixpkgs to easily build packages for other programming languages, such as
+  Perl or Haskell. These are described in this chapter.
+ </para>
+ <xi:include href="android.section.xml" />
+ <xi:include href="beam.xml" />
+ <xi:include href="bower.xml" />
+ <xi:include href="coq.xml" />
+ <xi:include href="go.xml" />
+ <xi:include href="haskell.section.xml" />
+ <xi:include href="idris.section.xml" />
+ <xi:include href="ios.section.xml" />
+ <xi:include href="java.xml" />
+ <xi:include href="lua.xml" />
+ <xi:include href="node.section.xml" />
+ <xi:include href="ocaml.xml" />
+ <xi:include href="perl.xml" />
+ <xi:include href="python.section.xml" />
+ <xi:include href="qt.xml" />
+ <xi:include href="r.section.xml" />
+ <xi:include href="ruby.xml" />
+ <xi:include href="rust.section.xml" />
+ <xi:include href="texlive.xml" />
+ <xi:include href="titanium.section.xml" />
+ <xi:include href="vim.section.xml" />
+ <xi:include href="emscripten.section.xml" />
+</chapter>
diff --git a/nixpkgs/doc/languages-frameworks/ios.section.md b/nixpkgs/doc/languages-frameworks/ios.section.md
new file mode 100644
index 000000000000..6684b809ffe6
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/ios.section.md
@@ -0,0 +1,219 @@
+---
+title: iOS
+author: Sander van der Burg
+date: 2018-11-18
+---
+# iOS
+
+This component is basically a wrapper/workaround that makes it possible to
+expose an Xcode installation as a Nix package by means of symlinking to the
+relevant executables on the host system.
+
+Since Xcode can't be packaged with Nix, nor we can publish it as a Nix package
+(because of its license) this is basically the only integration strategy
+making it possible to do iOS application builds that integrate with other
+components of the Nix ecosystem
+
+The primary objective of this project is to use the Nix expression language to
+specify how iOS apps can be built from source code, and to automatically spawn
+iOS simulator instances for testing.
+
+This component also makes it possible to use [Hydra](http://nixos.org/hydra),
+the Nix-based continuous integration server to regularly build iOS apps and to
+do wireless ad-hoc installations of enterprise IPAs on iOS devices through
+Hydra.
+
+The Xcode build environment implements a number of features.
+
+Deploying a proxy component wrapper exposing Xcode
+--------------------------------------------------
+The first use case is deploying a Nix package that provides symlinks to the Xcode
+installation on the host system. This package can be used as a build input to
+any build function implemented in the Nix expression language that requires
+Xcode.
+
+```nix
+let
+  pkgs = import <nixpkgs> {};
+
+  xcodeenv = import ./xcodeenv {
+    inherit (pkgs) stdenv;
+  };
+in
+xcodeenv.composeXcodeWrapper {
+  version = "9.2";
+  xcodeBaseDir = "/Applications/Xcode.app";
+}
+```
+
+By deploying the above expression with `nix-build` and inspecting its content
+you will notice that several Xcode-related executables are exposed as a Nix
+package:
+
+```bash
+$ ls result/bin
+lrwxr-xr-x  1 sander  staff  94  1 jan  1970 Simulator -> /Applications/Xcode.app/Contents/Developer/Applications/Simulator.app/Contents/MacOS/Simulator
+lrwxr-xr-x  1 sander  staff  17  1 jan  1970 codesign -> /usr/bin/codesign
+lrwxr-xr-x  1 sander  staff  17  1 jan  1970 security -> /usr/bin/security
+lrwxr-xr-x  1 sander  staff  21  1 jan  1970 xcode-select -> /usr/bin/xcode-select
+lrwxr-xr-x  1 sander  staff  61  1 jan  1970 xcodebuild -> /Applications/Xcode.app/Contents/Developer/usr/bin/xcodebuild
+lrwxr-xr-x  1 sander  staff  14  1 jan  1970 xcrun -> /usr/bin/xcrun
+```
+
+Building an iOS application
+---------------------------
+We can build an iOS app executable for the simulator, or an IPA/xcarchive file
+for release purposes, e.g. ad-hoc, enterprise or store installations, by
+executing the `xcodeenv.buildApp {}` function:
+
+```nix
+let
+  pkgs = import <nixpkgs> {};
+
+  xcodeenv = import ./xcodeenv {
+    inherit (pkgs) stdenv;
+  };
+in
+xcodeenv.buildApp {
+  name = "MyApp";
+  src = ./myappsources;
+  sdkVersion = "11.2";
+
+  target = null; # Corresponds to the name of the app by default
+  configuration = null; # Release for release builds, Debug for debug builds
+  scheme = null; # -scheme will correspond to the app name by default
+  sdk = null; # null will set it to 'iphonesimulator` for simulator builds or `iphoneos` to real builds
+  xcodeFlags = "";
+
+  release = true;
+  certificateFile = ./mycertificate.p12;
+  certificatePassword = "secret";
+  provisioningProfile = ./myprovisioning.profile;
+  signMethod = "ad-hoc"; # 'enterprise' or 'store'
+  generateIPA = true;
+  generateXCArchive = false;
+
+  enableWirelessDistribution = true;
+  installURL = "/installipa.php";
+  bundleId = "mycompany.myapp";
+  appVersion = "1.0";
+
+  # Supports all xcodewrapper parameters as well
+  xcodeBaseDir = "/Applications/Xcode.app";
+}
+```
+
+The above function takes a variety of parameters:
+* The `name` and `src` parameters are mandatory and specify the name of the app
+  and the location where the source code resides
+* `sdkVersion` specifies which version of the iOS SDK to use.
+
+It also possile to adjust the `xcodebuild` parameters. This is only needed in
+rare circumstances. In most cases the default values should suffice:
+
+* Specifies which `xcodebuild` target to build. By default it takes the target
+  that has the same name as the app.
+* The `configuration` parameter can be overridden if desired. By default, it
+  will do a debug build for the simulator and a release build for real devices.
+* The `scheme` parameter specifies which `-scheme` parameter to propagate to
+  `xcodebuild`. By default, it corresponds to the app name.
+* The `sdk` parameter specifies which SDK to use. By default, it picks
+  `iphonesimulator` for simulator builds and `iphoneos` for release builds.
+* The `xcodeFlags` parameter specifies arbitrary command line parameters that
+  should be propagated to `xcodebuild`.
+
+By default, builds are carried out for the iOS simulator. To do release builds
+(builds for real iOS devices), you must set the `release` parameter to `true`.
+In addition, you need to set the following parameters:
+
+* `certificateFile` refers to a P12 certificate file.
+* `certificatePassword` specifies the password of the P12 certificate.
+* `provisioningProfile` refers to the provision profile needed to sign the app
+* `signMethod` should refer to `ad-hoc` for signing the app with an ad-hoc
+  certificate, `enterprise` for enterprise certificates and `app-store` for App
+  store certificates.
+* `generateIPA` specifies that we want to produce an IPA file (this is probably
+  what you want)
+* `generateXCArchive` specifies thet we want to produce an xcarchive file.
+
+When building IPA files on Hydra and when it is desired to allow iOS devices to
+install IPAs by browsing to the Hydra build products page, you can enable the
+`enableWirelessDistribution` parameter.
+
+When enabled, you need to configure the following options:
+
+* The `installURL` parameter refers to the URL of a PHP script that composes the
+  `itms-services://` URL allowing iOS devices to install the IPA file.
+* `bundleId` refers to the bundle ID value of the app
+* `appVersion` refers to the app's version number
+
+To use wireless adhoc distributions, you must also install the corresponding
+PHP script on a web server (see section: 'Installing the PHP script for wireless
+ad hoc installations from Hydra' for more information).
+
+In addition to the build parameters, you can also specify any parameters that
+the `xcodeenv.composeXcodeWrapper {}` function takes. For example, the
+`xcodeBaseDir` parameter can be overridden to refer to a different Xcode
+version.
+
+Spawning simulator instances
+----------------------------
+In addition to building iOS apps, we can also automatically spawn simulator
+instances:
+
+```nix
+let
+  pkgs = import <nixpkgs> {};
+
+  xcodeenv = import ./xcodeenv {
+    inherit (pkgs) stdenv;
+  };
+in
+xcode.simulateApp {
+  name = "simulate";
+
+  # Supports all xcodewrapper parameters as well
+  xcodeBaseDir = "/Applications/Xcode.app";
+}
+```
+
+The above expression produces a script that starts the simulator from the
+provided Xcode installation. The script can be started as follows:
+
+```bash
+./result/bin/run-test-simulator
+```
+
+By default, the script will show an overview of UDID for all available simulator
+instances and asks you to pick one. You can also provide a UDID as a
+command-line parameter to launch an instance automatically:
+
+```bash
+./result/bin/run-test-simulator 5C93129D-CF39-4B1A-955F-15180C3BD4B8
+```
+
+You can also extend the simulator script to automatically deploy and launch an
+app in the requested simulator instance:
+
+```nix
+let
+  pkgs = import <nixpkgs> {};
+
+  xcodeenv = import ./xcodeenv {
+    inherit (pkgs) stdenv;
+  };
+in
+xcode.simulateApp {
+  name = "simulate";
+  bundleId = "mycompany.myapp";
+  app = xcode.buildApp {
+    # ...
+  };
+
+  # Supports all xcodewrapper parameters as well
+  xcodeBaseDir = "/Applications/Xcode.app";
+}
+```
+
+By providing the result of an `xcode.buildApp {}` function and configuring the
+app bundle id, the app gets deployed automatically and started.
diff --git a/nixpkgs/doc/languages-frameworks/java.xml b/nixpkgs/doc/languages-frameworks/java.xml
new file mode 100644
index 000000000000..667a795a8d3a
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/java.xml
@@ -0,0 +1,84 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-java">
+ <title>Java</title>
+
+ <para>
+  Ant-based Java packages are typically built from source as follows:
+<programlisting>
+stdenv.mkDerivation {
+  name = "...";
+  src = fetchurl { ... };
+
+  buildInputs = [ jdk ant ];
+
+  buildPhase = "ant";
+}
+</programlisting>
+  Note that <varname>jdk</varname> is an alias for the OpenJDK (self-built
+  where available, or pre-built via Zulu). Platforms with OpenJDK not (yet) in
+  Nixpkgs (<literal>Aarch32</literal>, <literal>Aarch64</literal>) point to the
+  (unfree) <literal>oraclejdk</literal>.
+ </para>
+
+ <para>
+  JAR files that are intended to be used by other packages should be installed
+  in <filename>$out/share/java</filename>. JDKs have a stdenv setup hook that
+  add any JARs in the <filename>share/java</filename> directories of the build
+  inputs to the <envar>CLASSPATH</envar> environment variable. For instance, if
+  the package <literal>libfoo</literal> installs a JAR named
+  <filename>foo.jar</filename> in its <filename>share/java</filename>
+  directory, and another package declares the attribute
+<programlisting>
+buildInputs = [ jdk libfoo ];
+</programlisting>
+  then <envar>CLASSPATH</envar> will be set to
+  <filename>/nix/store/...-libfoo/share/java/foo.jar</filename>.
+ </para>
+
+ <para>
+  Private JARs should be installed in a location like
+  <filename>$out/share/<replaceable>package-name</replaceable></filename>.
+ </para>
+
+ <para>
+  If your Java package provides a program, you need to generate a wrapper
+  script to run it using the OpenJRE. You can use
+  <literal>makeWrapper</literal> for this:
+<programlisting>
+buildInputs = [ makeWrapper ];
+
+installPhase =
+  ''
+    mkdir -p $out/bin
+    makeWrapper ${jre}/bin/java $out/bin/foo \
+      --add-flags "-cp $out/share/java/foo.jar org.foo.Main"
+  '';
+</programlisting>
+  Note the use of <literal>jre</literal>, which is the part of the OpenJDK
+  package that contains the Java Runtime Environment. By using
+  <literal>${jre}/bin/java</literal> instead of
+  <literal>${jdk}/bin/java</literal>, you prevent your package from depending
+  on the JDK at runtime.
+ </para>
+
+ <para>
+  Note all JDKs passthru <literal>home</literal>, so if your application
+  requires environment variables like <envar>JAVA_HOME</envar> being set, that
+  can be done in a generic fashion with the <literal>--set</literal> argument
+  of <literal>makeWrapper</literal>:
+<programlisting>
+  --set JAVA_HOME ${jdk.home}
+</programlisting>
+ </para>
+
+ <para>
+  It is possible to use a different Java compiler than <command>javac</command>
+  from the OpenJDK. For instance, to use the GNU Java Compiler:
+<programlisting>
+buildInputs = [ gcj ant ];
+</programlisting>
+  Here, Ant will automatically use <command>gij</command> (the GNU Java
+  Runtime) instead of the OpenJRE.
+ </para>
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/lua.xml b/nixpkgs/doc/languages-frameworks/lua.xml
new file mode 100644
index 000000000000..210140299960
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/lua.xml
@@ -0,0 +1,48 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-lua">
+ <title>Lua</title>
+
+ <para>
+  Lua packages are built by the <varname>buildLuaPackage</varname> function.
+  This function is implemented in
+  <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/lua-modules/generic/default.nix">
+  <filename>pkgs/development/lua-modules/generic/default.nix</filename></link>
+  and works similarly to <varname>buildPerlPackage</varname>. (See
+  <xref linkend="sec-language-perl"/> for details.)
+ </para>
+
+ <para>
+  Lua packages are defined in
+  <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/lua-packages.nix"><filename>pkgs/top-level/lua-packages.nix</filename></link>.
+  Most of them are simple. For example:
+<programlisting>
+fileSystem = buildLuaPackage {
+  name = "filesystem-1.6.2";
+  src = fetchurl {
+    url = "https://github.com/keplerproject/luafilesystem/archive/v1_6_2.tar.gz";
+    sha256 = "1n8qdwa20ypbrny99vhkmx8q04zd2jjycdb5196xdhgvqzk10abz";
+  };
+  meta = {
+    homepage = "https://github.com/keplerproject/luafilesystem";
+    hydraPlatforms = stdenv.lib.platforms.linux;
+    maintainers = with maintainers; [ flosse ];
+  };
+};
+  </programlisting>
+ </para>
+
+ <para>
+  Though, more complicated package should be placed in a seperate file in
+  <link
+  xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/lua-modules"><filename>pkgs/development/lua-modules</filename></link>.
+ </para>
+
+ <para>
+  Lua packages accept additional parameter <varname>disabled</varname>, which
+  defines the condition of disabling package from luaPackages. For example, if
+  package has <varname>disabled</varname> assigned to <literal>lua.luaversion
+  != "5.1"</literal>, it will not be included in any luaPackages except
+  lua51Packages, making it only be built for lua 5.1.
+ </para>
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/node.section.md b/nixpkgs/doc/languages-frameworks/node.section.md
new file mode 100644
index 000000000000..c6dce04c7b8b
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/node.section.md
@@ -0,0 +1,51 @@
+Node.js packages
+================
+The `pkgs/development/node-packages` folder contains a generated collection of
+[NPM packages](https://npmjs.com/) that can be installed with the Nix package
+manager.
+
+As a rule of thumb, the package set should only provide *end user* software
+packages, such as command-line utilities. Libraries should only be added to the
+package set if there is a non-NPM package that requires it.
+
+When it is desired to use NPM libraries in a development project, use the
+`node2nix` generator directly on the `package.json` configuration file of the
+project.
+
+The package set also provides support for multiple Node.js versions. The policy
+is that a new package should be added to the collection for the latest stable LTS
+release (which is currently 10.x), unless there is an explicit reason to support
+a different release.
+
+If your package uses native addons, you need to examine what kind of native
+build system it uses. Here are some examples:
+
+* `node-gyp`
+* `node-gyp-builder`
+* `node-pre-gyp`
+
+After you have identified the correct system, you need to override your package
+expression while adding in build system as a build input. For example, `dat`
+requires `node-gyp-build`, so we override its expression in `default-v10.nix`:
+
+```nix
+dat = nodePackages.dat.override (oldAttrs: {
+  buildInputs = oldAttrs.buildInputs ++ [ nodePackages.node-gyp-build ];
+});
+```
+
+To add a package from NPM to nixpkgs:
+
+ 1. Modify `pkgs/development/node-packages/node-packages-v10.json` to add, update
+    or remove package entries. (Or `pkgs/development/node-packages/node-packages-v8.json`
+    for packages depending on Node.js 8.x)
+ 2. Run the script: `(cd pkgs/development/node-packages && ./generate.sh)`.
+ 3. Build your new package to test your changes:
+    `cd /path/to/nixpkgs && nix-build -A nodePackages.<new-or-updated-package>`.
+    To build against a specific Node.js version (e.g. 10.x):
+    `nix-build -A nodePackages_10_x.<new-or-updated-package>`
+ 4. Add and commit all modified and generated files.
+
+For more information about the generation process, consult the
+[README.md](https://github.com/svanderburg/node2nix) file of the `node2nix`
+tool.
diff --git a/nixpkgs/doc/languages-frameworks/ocaml.xml b/nixpkgs/doc/languages-frameworks/ocaml.xml
new file mode 100644
index 000000000000..ea0770616802
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/ocaml.xml
@@ -0,0 +1,99 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-ocaml">
+ <title>OCaml</title>
+
+ <para>
+   OCaml libraries should be installed in
+   <literal>$(out)/lib/ocaml/${ocaml.version}/site-lib/</literal>. Such
+   directories are automatically added to the <literal>$OCAMLPATH</literal>
+   environment variable when building another package that depends on them
+   or when opening a <literal>nix-shell</literal>.
+ </para>
+
+ <para>
+   Given that most of the OCaml ecosystem is now built with dune,
+   nixpkgs includes a convenience build support function called
+   <literal>buildDunePackage</literal> that will build an OCaml package
+   using dune, OCaml and findlib and any additional dependencies provided
+   as <literal>buildInputs</literal> or <literal>propagatedBuildInputs</literal>.
+ </para>
+
+ <para>
+   Here is a simple package example. It defines an (optional) attribute
+   <literal>minimumOCamlVersion</literal> that will be used to throw a
+   descriptive evaluation error if building with an older OCaml is attempted.
+   It uses the <literal>fetchFromGitHub</literal> fetcher to get its source.
+   It sets the <literal>doCheck</literal> (optional) attribute to
+   <literal>true</literal> which means that tests will be run with
+   <literal>dune runtest -p angstrom</literal> after the build
+   (<literal>dune build -p angstrom</literal>) is complete.
+   It uses <literal>alcotest</literal> as a build input (because it is needed
+   to run the tests) and <literal>bigstringaf</literal> and
+   <literal>result</literal> as propagated build inputs (thus they will also
+   be available to libraries depending on this library).
+   The library will be installed using the <literal>angstrom.install</literal>
+   file that dune generates.
+ </para>
+
+ <programlisting>
+{ stdenv, fetchFromGitHub, buildDunePackage, alcotest, result, bigstringaf }:
+
+buildDunePackage rec {
+  pname = "angstrom";
+  version = "0.10.0";
+
+  minimumOCamlVersion = "4.03";
+
+  src = fetchFromGitHub {
+    owner  = "inhabitedtype";
+    repo   = pname;
+    rev    = version;
+    sha256 = "0lh6024yf9ds0nh9i93r9m6p5psi8nvrqxl5x7jwl13zb0r9xfpw";
+  };
+
+  buildInputs = [ alcotest ];
+  propagatedBuildInputs = [ bigstringaf result ];
+  doCheck = true;
+
+  meta = {
+    homepage = https://github.com/inhabitedtype/angstrom;
+    description = "OCaml parser combinators built for speed and memory efficiency";
+    license = stdenv.lib.licenses.bsd3;
+    maintainers = with stdenv.lib.maintainers; [ sternenseemann ];
+  };
+}
+ </programlisting>
+
+ <para>
+   Here is a second example, this time using a source archive generated with
+   <literal>dune-release</literal>. It is a good idea to use this archive when
+   it is available as it will usually contain substituted variables such as a
+   <literal>%%VERSION%%</literal> field. This library does not depend
+   on any other OCaml library and no tests are run after building it.
+ </para>
+
+ <programlisting>
+{ stdenv, fetchurl, buildDunePackage }:
+
+buildDunePackage rec {
+  pname = "wtf8";
+  version = "1.0.1";
+
+  minimumOCamlVersion = "4.01";
+
+  src = fetchurl {
+    url = "https://github.com/flowtype/ocaml-${pname}/releases/download/v${version}/${pname}-${version}.tbz";
+    sha256 = "1msg3vycd3k8qqj61sc23qks541cxpb97vrnrvrhjnqxsqnh6ygq";
+  };
+
+  meta = with stdenv.lib; {
+    homepage = https://github.com/flowtype/ocaml-wtf8;
+    description = "WTF-8 is a superset of UTF-8 that allows unpaired surrogates.";
+    license = licenses.mit;
+    maintainers = [ maintainers.eqyiel ];
+  };
+}
+ </programlisting>
+
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/perl.xml b/nixpkgs/doc/languages-frameworks/perl.xml
new file mode 100644
index 000000000000..a675e6665863
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/perl.xml
@@ -0,0 +1,192 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-perl">
+ <title>Perl</title>
+
+ <para>
+  Nixpkgs provides a function <varname>buildPerlPackage</varname>, a generic
+  package builder function for any Perl package that has a standard
+  <varname>Makefile.PL</varname>. It’s implemented in
+  <link
+xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/perl-modules/generic"><filename>pkgs/development/perl-modules/generic</filename></link>.
+ </para>
+
+ <para>
+  Perl packages from CPAN are defined in
+  <link
+xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix"><filename>pkgs/top-level/perl-packages.nix</filename></link>,
+  rather than <filename>pkgs/all-packages.nix</filename>. Most Perl packages
+  are so straight-forward to build that they are defined here directly, rather
+  than having a separate function for each package called from
+  <filename>perl-packages.nix</filename>. However, more complicated packages
+  should be put in a separate file, typically in
+  <filename>pkgs/development/perl-modules</filename>. Here is an example of the
+  former:
+<programlisting>
+ClassC3 = buildPerlPackage rec {
+  name = "Class-C3-0.21";
+  src = fetchurl {
+    url = "mirror://cpan/authors/id/F/FL/FLORA/${name}.tar.gz";
+    sha256 = "1bl8z095y4js66pwxnm7s853pi9czala4sqc743fdlnk27kq94gz";
+  };
+};
+</programlisting>
+  Note the use of <literal>mirror://cpan/</literal>, and the
+  <literal>${name}</literal> in the URL definition to ensure that the name
+  attribute is consistent with the source that we’re actually downloading.
+  Perl packages are made available in <filename>all-packages.nix</filename>
+  through the variable <varname>perlPackages</varname>. For instance, if you
+  have a package that needs <varname>ClassC3</varname>, you would typically
+  write
+<programlisting>
+foo = import ../path/to/foo.nix {
+  inherit stdenv fetchurl ...;
+  inherit (perlPackages) ClassC3;
+};
+</programlisting>
+  in <filename>all-packages.nix</filename>. You can test building a Perl
+  package as follows:
+<screen>
+$ nix-build -A perlPackages.ClassC3
+</screen>
+  <varname>buildPerlPackage</varname> adds <literal>perl-</literal> to the
+  start of the name attribute, so the package above is actually called
+  <literal>perl-Class-C3-0.21</literal>. So to install it, you can say:
+<screen>
+$ nix-env -i perl-Class-C3
+</screen>
+  (Of course you can also install using the attribute name: <literal>nix-env -i
+  -A perlPackages.ClassC3</literal>.)
+ </para>
+
+ <para>
+  So what does <varname>buildPerlPackage</varname> do? It does the following:
+  <orderedlist>
+   <listitem>
+    <para>
+     In the configure phase, it calls <literal>perl Makefile.PL</literal> to
+     generate a Makefile. You can set the variable
+     <varname>makeMakerFlags</varname> to pass flags to
+     <filename>Makefile.PL</filename>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     It adds the contents of the <envar>PERL5LIB</envar> environment variable
+     to <literal>#! .../bin/perl</literal> line of Perl scripts as
+     <literal>-I<replaceable>dir</replaceable></literal> flags. This ensures
+     that a script can find its dependencies.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     In the fixup phase, it writes the propagated build inputs
+     (<varname>propagatedBuildInputs</varname>) to the file
+     <filename>$out/nix-support/propagated-user-env-packages</filename>.
+     <command>nix-env</command> recursively installs all packages listed in
+     this file when you install a package that has it. This ensures that a Perl
+     package can find its dependencies.
+    </para>
+   </listitem>
+  </orderedlist>
+ </para>
+
+ <para>
+  <varname>buildPerlPackage</varname> is built on top of
+  <varname>stdenv</varname>, so everything can be customised in the usual way.
+  For instance, the <literal>BerkeleyDB</literal> module has a
+  <varname>preConfigure</varname> hook to generate a configuration file used by
+  <filename>Makefile.PL</filename>:
+<programlisting>
+{ buildPerlPackage, fetchurl, db }:
+
+buildPerlPackage rec {
+  name = "BerkeleyDB-0.36";
+
+  src = fetchurl {
+    url = "mirror://cpan/authors/id/P/PM/PMQS/${name}.tar.gz";
+    sha256 = "07xf50riarb60l1h6m2dqmql8q5dij619712fsgw7ach04d8g3z1";
+  };
+
+  preConfigure = ''
+    echo "LIB = ${db.out}/lib" > config.in
+    echo "INCLUDE = ${db.dev}/include" >> config.in
+  '';
+}
+</programlisting>
+ </para>
+
+ <para>
+  Dependencies on other Perl packages can be specified in the
+  <varname>buildInputs</varname> and <varname>propagatedBuildInputs</varname>
+  attributes. If something is exclusively a build-time dependency, use
+  <varname>buildInputs</varname>; if it’s (also) a runtime dependency, use
+  <varname>propagatedBuildInputs</varname>. For instance, this builds a Perl
+  module that has runtime dependencies on a bunch of other modules:
+<programlisting>
+ClassC3Componentised = buildPerlPackage rec {
+  name = "Class-C3-Componentised-1.0004";
+  src = fetchurl {
+    url = "mirror://cpan/authors/id/A/AS/ASH/${name}.tar.gz";
+    sha256 = "0xql73jkcdbq4q9m0b0rnca6nrlvf5hyzy8is0crdk65bynvs8q1";
+  };
+  propagatedBuildInputs = [
+    ClassC3 ClassInspector TestException MROCompat
+  ];
+};
+</programlisting>
+ </para>
+
+ <section xml:id="ssec-generation-from-CPAN">
+  <title>Generation from CPAN</title>
+
+  <para>
+   Nix expressions for Perl packages can be generated (almost) automatically
+   from CPAN. This is done by the program
+   <command>nix-generate-from-cpan</command>, which can be installed as
+   follows:
+  </para>
+
+<screen>
+$ nix-env -i nix-generate-from-cpan
+</screen>
+
+  <para>
+   This program takes a Perl module name, looks it up on CPAN, fetches and
+   unpacks the corresponding package, and prints a Nix expression on standard
+   output. For example:
+<screen>
+$ nix-generate-from-cpan XML::Simple
+  XMLSimple = buildPerlPackage rec {
+    name = "XML-Simple-2.22";
+    src = fetchurl {
+      url = "mirror://cpan/authors/id/G/GR/GRANTM/${name}.tar.gz";
+      sha256 = "b9450ef22ea9644ae5d6ada086dc4300fa105be050a2030ebd4efd28c198eb49";
+    };
+    propagatedBuildInputs = [ XMLNamespaceSupport XMLSAX XMLSAXExpat ];
+    meta = {
+      description = "An API for simple XML files";
+      license = with stdenv.lib.licenses; [ artistic1 gpl1Plus ];
+    };
+  };
+</screen>
+   The output can be pasted into
+   <filename>pkgs/top-level/perl-packages.nix</filename> or wherever else you
+   need it.
+  </para>
+ </section>
+
+ <section xml:id="ssec-perl-cross-compilation">
+  <title>Cross-compiling modules</title>
+
+  <para>
+   Nixpkgs has experimental support for cross-compiling Perl modules. In many
+   cases, it will just work out of the box, even for modules with native
+   extensions. Sometimes, however, the Makefile.PL for a module may
+   (indirectly) import a native module. In that case, you will need to make a
+   stub for that module that will satisfy the Makefile.PL and install it into
+   <filename>lib/perl5/site_perl/cross_perl/${perl.version}</filename>. See the
+   <varname>postInstall</varname> for <varname>DBI</varname> for an example.
+  </para>
+ </section>
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/python.section.md b/nixpkgs/doc/languages-frameworks/python.section.md
new file mode 100644
index 000000000000..acd2bf769b0d
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/python.section.md
@@ -0,0 +1,1138 @@
+# Python
+
+## User Guide
+
+### Using Python
+
+#### Overview
+
+Several versions of the Python interpreter are available on Nix, as well as a
+high amount of packages. The attribute `python` refers to the default
+interpreter, which is currently CPython 2.7. It is also possible to refer to
+specific versions, e.g. `python35` refers to CPython 3.5, and `pypy` refers to
+the default PyPy interpreter.
+
+Python is used a lot, and in different ways. This affects also how it is
+packaged. In the case of Python on Nix, an important distinction is made between
+whether the package is considered primarily an application, or whether it should
+be used as a library, i.e., of primary interest are the modules in
+`site-packages` that should be importable.
+
+In the Nixpkgs tree Python applications can be found throughout, depending on
+what they do, and are called from the main package set. Python libraries,
+however, are in separate sets, with one set per interpreter version.
+
+The interpreters have several common attributes. One of these attributes is
+`pkgs`, which is a package set of Python libraries for this specific
+interpreter. E.g., the `toolz` package corresponding to the default interpreter
+is `python.pkgs.toolz`, and the CPython 3.5 version is `python35.pkgs.toolz`.
+The main package set contains aliases to these package sets, e.g.
+`pythonPackages` refers to `python.pkgs` and `python35Packages` to
+`python35.pkgs`.
+
+#### Installing Python and packages
+
+The Nix and NixOS manuals explain how packages are generally installed. In the
+case of Python and Nix, it is important to make a distinction between whether the
+package is considered an application or a library.
+
+Applications on Nix are typically installed into your user
+profile imperatively using `nix-env -i`, and on NixOS declaratively by adding the
+package name to `environment.systemPackages` in `/etc/nixos/configuration.nix`.
+Dependencies such as libraries are automatically installed and should not be
+installed explicitly.
+
+The same goes for Python applications and libraries. Python applications can be
+installed in your profile. But Python libraries you would like to use for
+development cannot be installed, at least not individually, because they won't
+be able to find each other resulting in import errors. Instead, it is possible
+to create an environment with `python.buildEnv` or `python.withPackages` where
+the interpreter and other executables are able to find each other and all of the
+modules.
+
+In the following examples we create an environment with Python 3.5, `numpy` and
+`toolz`. As you may imagine, there is one limitation here, and that's that
+you can install only one environment at a time. You will notice the complaints
+about collisions when you try to install a second environment.
+
+##### Environment defined in separate `.nix` file
+
+Create a file, e.g. `build.nix`, with the following expression
+```nix
+with import <nixpkgs> {};
+
+python35.withPackages (ps: with ps; [ numpy toolz ])
+```
+and install it in your profile with
+```shell
+nix-env -if build.nix
+```
+Now you can use the Python interpreter, as well as the extra packages (`numpy`,
+`toolz`) that you added to the environment.
+
+##### Environment defined in `~/.config/nixpkgs/config.nix`
+
+If you prefer to, you could also add the environment as a package override to the Nixpkgs set, e.g.
+using `config.nix`,
+```nix
+{ # ...
+
+  packageOverrides = pkgs: with pkgs; {
+    myEnv = python35.withPackages (ps: with ps; [ numpy toolz ]);
+  };
+}
+```
+and install it in your profile with
+```shell
+nix-env -iA nixpkgs.myEnv
+```
+The environment is is installed by referring to the attribute, and considering
+the `nixpkgs` channel was used.
+
+##### Environment defined in `/etc/nixos/configuration.nix`
+
+For the sake of completeness, here's another example how to install the environment system-wide.
+
+```nix
+{ # ...
+
+  environment.systemPackages = with pkgs; [
+    (python35.withPackages(ps: with ps; [ numpy toolz ]))
+  ];
+}
+```
+
+#### Temporary Python environment with `nix-shell`
+
+The examples in the previous section showed how to install a Python environment
+into a profile. For development you may need to use multiple environments.
+`nix-shell` gives the possibility to temporarily load another environment, akin
+to `virtualenv`.
+
+There are two methods for loading a shell with Python packages. The first and recommended method
+is to create an environment with `python.buildEnv` or `python.withPackages` and load that. E.g.
+```sh
+$ nix-shell -p 'python35.withPackages(ps: with ps; [ numpy toolz ])'
+```
+opens a shell from which you can launch the interpreter
+```sh
+[nix-shell:~] python3
+```
+The other method, which is not recommended, does not create an environment and requires you to list the packages directly,
+
+```sh
+$ nix-shell -p python35.pkgs.numpy python35.pkgs.toolz
+```
+Again, it is possible to launch the interpreter from the shell.
+The Python interpreter has the attribute `pkgs` which contains all Python libraries for that specific interpreter.
+
+##### Load environment from `.nix` expression
+As explained in the Nix manual, `nix-shell` can also load an
+expression from a `.nix` file. Say we want to have Python 3.5, `numpy`
+and `toolz`, like before, in an environment. Consider a `shell.nix` file
+with
+```nix
+with import <nixpkgs> {};
+
+(python35.withPackages (ps: [ps.numpy ps.toolz])).env
+```
+Executing `nix-shell` gives you again a Nix shell from which you can run Python.
+
+What's happening here?
+
+1. We begin with importing the Nix Packages collections. `import <nixpkgs>` imports the `<nixpkgs>` function, `{}` calls it and the `with` statement brings all attributes of `nixpkgs` in the local scope. These attributes form the main package set.
+2. Then we create a Python 3.5 environment with the `withPackages` function.
+3. The `withPackages` function expects us to provide a function as an argument that takes the set of all python packages and returns a list of packages to include in the environment. Here, we select the packages `numpy` and `toolz` from the package set.
+
+##### Execute command with `--run`
+A convenient option with `nix-shell` is the `--run`
+option, with which you can execute a command in the `nix-shell`. We can
+e.g. directly open a Python shell
+```sh
+$ nix-shell -p python35Packages.numpy python35Packages.toolz --run "python3"
+```
+or run a script
+```sh
+$ nix-shell -p python35Packages.numpy python35Packages.toolz --run "python3 myscript.py"
+```
+
+##### `nix-shell` as shebang
+In fact, for the second use case, there is a more convenient method. You can
+add a [shebang](https://en.wikipedia.org/wiki/Shebang_(Unix)) to your script
+specifying which dependencies `nix-shell` needs. With the following shebang, you
+can just execute `./myscript.py`, and it will make available all dependencies and
+run the script in the `python3` shell.
+
+```py
+#! /usr/bin/env nix-shell
+#! nix-shell -i python3 -p "python3.withPackages(ps: [ps.numpy])"
+
+import numpy
+
+print(numpy.__version__)
+```
+
+### Developing with Python
+
+Now that you know how to get a working Python environment with Nix, it is time
+to go forward and start actually developing with Python. We will first have a
+look at how Python packages are packaged on Nix. Then, we will look at how you
+can use development mode with your code.
+
+#### Packaging a library
+
+With Nix all packages are built by functions. The main function in Nix for
+building Python libraries is `buildPythonPackage`. Let's see how we can build the
+`toolz` package.
+
+```nix
+{ lib, buildPythonPackage, fetchPypi }:
+
+  toolz = buildPythonPackage rec {
+    pname = "toolz";
+    version = "0.7.4";
+
+    src = fetchPypi {
+      inherit pname version;
+      sha256 = "43c2c9e5e7a16b6c88ba3088a9bfc82f7db8e13378be7c78d6c14a5f8ed05afd";
+    };
+
+    doCheck = false;
+
+    meta = with lib; {
+      homepage = https://github.com/pytoolz/toolz;
+      description = "List processing tools and functional utilities";
+      license = licenses.bsd3;
+      maintainers = with maintainers; [ fridh ];
+    };
+  };
+}
+```
+
+What happens here? The function `buildPythonPackage` is called and as argument
+it accepts a set. In this case the set is a recursive set, `rec`. One of the
+arguments is the name of the package, which consists of a basename (generally
+following the name on PyPi) and a version. Another argument, `src` specifies the
+source, which in this case is fetched from PyPI using the helper function
+`fetchPypi`. The argument `doCheck` is used to set whether tests should be run
+when building the package. Furthermore, we specify some (optional) meta
+information. The output of the function is a derivation.
+
+An expression for `toolz` can be found in the Nixpkgs repository. As explained
+in the introduction of this Python section, a derivation of `toolz` is available
+for each interpreter version, e.g. `python35.pkgs.toolz` refers to the `toolz`
+derivation corresponding to the CPython 3.5 interpreter.
+The above example works when you're directly working on
+`pkgs/top-level/python-packages.nix` in the Nixpkgs repository. Often though,
+you will want to test a Nix expression outside of the Nixpkgs tree.
+
+The following expression creates a derivation for the `toolz` package,
+and adds it along with a `numpy` package to a Python environment.
+
+```nix
+with import <nixpkgs> {};
+
+( let
+    my_toolz = python35.pkgs.buildPythonPackage rec {
+      pname = "toolz";
+      version = "0.7.4";
+
+      src = python35.pkgs.fetchPypi {
+        inherit pname version;
+        sha256 = "43c2c9e5e7a16b6c88ba3088a9bfc82f7db8e13378be7c78d6c14a5f8ed05afd";
+      };
+
+      doCheck = false;
+
+      meta = {
+        homepage = "https://github.com/pytoolz/toolz/";
+        description = "List processing tools and functional utilities";
+      };
+    };
+
+  in python35.withPackages (ps: [ps.numpy my_toolz])
+).env
+```
+Executing `nix-shell` will result in an environment in which you can use
+Python 3.5 and the `toolz` package. As you can see we had to explicitly mention
+for which Python version we want to build a package.
+
+So, what did we do here? Well, we took the Nix expression that we used earlier
+to build a Python environment, and said that we wanted to include our own
+version of `toolz`, named `my_toolz`. To introduce our own package in the scope
+of `withPackages` we used a `let` expression. You can see that we used
+`ps.numpy` to select numpy from the nixpkgs package set (`ps`). We did not take
+`toolz` from the Nixpkgs package set this time, but instead took our own version
+that we introduced with the `let` expression.
+
+#### Handling dependencies
+
+Our example, `toolz`, does not have any dependencies on other Python packages or
+system libraries. According to the manual, `buildPythonPackage` uses the
+arguments `buildInputs` and `propagatedBuildInputs` to specify dependencies. If
+something is exclusively a build-time dependency, then the dependency should be
+included as a `buildInput`, but if it is (also) a runtime dependency, then it
+should be added to `propagatedBuildInputs`. Test dependencies are considered
+build-time dependencies and passed to `checkInputs`.
+
+The following example shows which arguments are given to `buildPythonPackage` in
+order to build [`datashape`](https://github.com/blaze/datashape).
+
+```nix
+{ # ...
+
+  datashape = buildPythonPackage rec {
+    pname = "datashape";
+    version = "0.4.7";
+
+    src = fetchPypi {
+      inherit pname version;
+      sha256 = "14b2ef766d4c9652ab813182e866f493475e65e558bed0822e38bf07bba1a278";
+    };
+
+    checkInputs = with self; [ pytest ];
+    propagatedBuildInputs = with self; [ numpy multipledispatch dateutil ];
+
+    meta = with lib; {
+      homepage = https://github.com/ContinuumIO/datashape;
+      description = "A data description language";
+      license = licenses.bsd2;
+      maintainers = with maintainers; [ fridh ];
+    };
+  };
+}
+```
+
+We can see several runtime dependencies, `numpy`, `multipledispatch`, and
+`dateutil`. Furthermore, we have one `buildInput`, i.e. `pytest`. `pytest` is a
+test runner and is only used during the `checkPhase` and is therefore not added
+to `propagatedBuildInputs`.
+
+In the previous case we had only dependencies on other Python packages to consider.
+Occasionally you have also system libraries to consider. E.g., `lxml` provides
+Python bindings to `libxml2` and `libxslt`. These libraries are only required
+when building the bindings and are therefore added as `buildInputs`.
+
+```nix
+{ # ...
+
+  lxml = buildPythonPackage rec {
+    pname = "lxml";
+    version = "3.4.4";
+
+    src = fetchPypi {
+      inherit pname version;
+      sha256 = "16a0fa97hym9ysdk3rmqz32xdjqmy4w34ld3rm3jf5viqjx65lxk";
+    };
+
+    buildInputs = with self; [ pkgs.libxml2 pkgs.libxslt ];
+
+    meta = with lib; {
+      description = "Pythonic binding for the libxml2 and libxslt libraries";
+      homepage = https://lxml.de;
+      license = licenses.bsd3;
+      maintainers = with maintainers; [ sjourdois ];
+    };
+  };
+}
+```
+
+In this example `lxml` and Nix are able to work out exactly where the relevant
+files of the dependencies are. This is not always the case.
+
+The example below shows bindings to The Fastest Fourier Transform in the West, commonly known as
+FFTW. On Nix we have separate packages of FFTW for the different types of floats
+(`"single"`, `"double"`, `"long-double"`). The bindings need all three types,
+and therefore we add all three as `buildInputs`. The bindings don't expect to
+find each of them in a different folder, and therefore we have to set `LDFLAGS`
+and `CFLAGS`.
+
+```nix
+{ # ...
+
+  pyfftw = buildPythonPackage rec {
+    pname = "pyFFTW";
+    version = "0.9.2";
+
+    src = fetchPypi {
+      inherit pname version;
+      sha256 = "f6bbb6afa93085409ab24885a1a3cdb8909f095a142f4d49e346f2bd1b789074";
+    };
+
+    buildInputs = [ pkgs.fftw pkgs.fftwFloat pkgs.fftwLongDouble];
+
+    propagatedBuildInputs = with self; [ numpy scipy ];
+
+    # Tests cannot import pyfftw. pyfftw works fine though.
+    doCheck = false;
+
+    preConfigure = ''
+      export LDFLAGS="-L${pkgs.fftw.dev}/lib -L${pkgs.fftwFloat.out}/lib -L${pkgs.fftwLongDouble.out}/lib"
+      export CFLAGS="-I${pkgs.fftw.dev}/include -I${pkgs.fftwFloat.dev}/include -I${pkgs.fftwLongDouble.dev}/include"
+    '';
+
+    meta = with lib; {
+      description = "A pythonic wrapper around FFTW, the FFT library, presenting a unified interface for all the supported transforms";
+      homepage = http://hgomersall.github.com/pyFFTW;
+      license = with licenses; [ bsd2 bsd3 ];
+      maintainers = with maintainers; [ fridh ];
+    };
+  };
+}
+```
+Note also the line `doCheck = false;`, we explicitly disabled running the test-suite.
+
+
+#### Develop local package
+
+As a Python developer you're likely aware of [development mode](http://setuptools.readthedocs.io/en/latest/setuptools.html#development-mode) (`python setup.py develop`);
+instead of installing the package this command creates a special link to the project code.
+That way, you can run updated code without having to reinstall after each and every change you make.
+Development mode is also available. Let's see how you can use it.
+
+In the previous Nix expression the source was fetched from an url. We can also refer to a local source instead using
+`src = ./path/to/source/tree;`
+
+If we create a `shell.nix` file which calls `buildPythonPackage`, and if `src`
+is a local source, and if the local source has a `setup.py`, then development
+mode is activated.
+
+In the following example we create a simple environment that
+has a Python 3.5 version of our package in it, as well as its dependencies and
+other packages we like to have in the environment, all specified with `propagatedBuildInputs`.
+Indeed, we can just add any package we like to have in our environment to `propagatedBuildInputs`.
+
+```nix
+with import <nixpkgs> {};
+with pkgs.python35Packages;
+
+buildPythonPackage rec {
+  name = "mypackage";
+  src = ./path/to/package/source;
+  propagatedBuildInputs = [ pytest numpy pkgs.libsndfile ];
+}
+```
+
+It is important to note that due to how development mode is implemented on Nix it is not possible to have multiple packages simultaneously in development mode.
+
+
+### Organising your packages
+
+So far we discussed how you can use Python on Nix, and how you can develop with
+it. We've looked at how you write expressions to package Python packages, and we
+looked at how you can create environments in which specified packages are
+available.
+
+At some point you'll likely have multiple packages which you would
+like to be able to use in different projects. In order to minimise unnecessary
+duplication we now look at how you can maintain a repository with your
+own packages. The important functions here are `import` and `callPackage`.
+
+### Including a derivation using `callPackage`
+
+Earlier we created a Python environment using `withPackages`, and included the
+`toolz` package via a `let` expression.
+Let's split the package definition from the environment definition.
+
+We first create a function that builds `toolz` in `~/path/to/toolz/release.nix`
+
+```nix
+{ lib, pkgs, buildPythonPackage }:
+
+buildPythonPackage rec {
+  pname = "toolz";
+  version = "0.7.4";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "43c2c9e5e7a16b6c88ba3088a9bfc82f7db8e13378be7c78d6c14a5f8ed05afd";
+  };
+
+  meta = with lib; {
+    homepage = "http://github.com/pytoolz/toolz/";
+    description = "List processing tools and functional utilities";
+    license = licenses.bsd3;
+    maintainers = with maintainers; [ fridh ];
+  };
+}
+```
+
+It takes two arguments, `pkgs` and `buildPythonPackage`.
+We now call this function using `callPackage` in the definition of our environment
+
+```nix
+with import <nixpkgs> {};
+
+( let
+    toolz = pkgs.callPackage /path/to/toolz/release.nix {
+      pkgs = pkgs;
+      buildPythonPackage = pkgs.python35Packages.buildPythonPackage;
+    };
+  in pkgs.python35.withPackages (ps: [ ps.numpy toolz ])
+).env
+```
+
+Important to remember is that the Python version for which the package is made
+depends on the `python` derivation that is passed to `buildPythonPackage`. Nix
+tries to automatically pass arguments when possible, which is why generally you
+don't explicitly define which `python` derivation should be used. In the above
+example we use `buildPythonPackage` that is part of the set `python35Packages`,
+and in this case the `python35` interpreter is automatically used.
+
+## Reference
+
+### Interpreters
+
+Versions 2.7, 3.5, 3.6 and 3.7 of the CPython interpreter are available as
+respectively `python27`, `python35`, `python36` and `python37`. The aliases
+`python2` and `python3` correspond to respectively `python27` and
+`python37`. The default interpreter, `python`, maps to `python2`. The PyPy
+interpreters compatible with Python 2.7 and 3 are available as `pypy27` and
+`pypy3`, with aliases `pypy2` mapping to `pypy27` and `pypy` mapping to
+`pypy2`. The Nix expressions for the interpreters can be
+found in `pkgs/development/interpreters/python`.
+
+All packages depending on any Python interpreter get appended
+`out/{python.sitePackages}` to `$PYTHONPATH` if such directory
+exists.
+
+#### Missing `tkinter` module standard library
+
+To reduce closure size the `Tkinter`/`tkinter` is available as a separate package, `pythonPackages.tkinter`.
+
+#### Attributes on interpreters packages
+
+Each interpreter has the following attributes:
+
+- `libPrefix`. Name of the folder in `${python}/lib/` for corresponding interpreter.
+- `interpreter`. Alias for `${python}/bin/${executable}`.
+- `buildEnv`. Function to build python interpreter environments with extra packages bundled together. See section *python.buildEnv function* for usage and documentation.
+- `withPackages`. Simpler interface to `buildEnv`. See section *python.withPackages function* for usage and documentation.
+- `sitePackages`. Alias for `lib/${libPrefix}/site-packages`.
+- `executable`. Name of the interpreter executable, e.g. `python3.7`.
+- `pkgs`. Set of Python packages for that specific interpreter. The package set can be modified by overriding the interpreter and passing `packageOverrides`.
+
+### Building packages and applications
+
+Python libraries and applications that use `setuptools` or
+`distutils` are typically build with respectively the `buildPythonPackage` and
+`buildPythonApplication` functions. These two functions also support installing a `wheel`.
+
+All Python packages reside in `pkgs/top-level/python-packages.nix` and all
+applications elsewhere. In case a package is used as both a library and an application,
+then the package should be in `pkgs/top-level/python-packages.nix` since only those packages are made
+available for all interpreter versions. The preferred location for library expressions is in
+`pkgs/development/python-modules`. It is important that these packages are
+called from `pkgs/top-level/python-packages.nix` and not elsewhere, to guarantee
+the right version of the package is built.
+
+Based on the packages defined in `pkgs/top-level/python-packages.nix` an
+attribute set is created for each available Python interpreter. The available
+sets are
+
+* `pkgs.python27Packages`
+* `pkgs.python35Packages`
+* `pkgs.python36Packages`
+* `pkgs.python37Packages`
+* `pkgs.pypyPackages`
+
+and the aliases
+
+* `pkgs.python2Packages` pointing to `pkgs.python27Packages`
+* `pkgs.python3Packages` pointing to `pkgs.python37Packages`
+* `pkgs.pythonPackages` pointing to `pkgs.python2Packages`
+
+#### `buildPythonPackage` function
+
+The `buildPythonPackage` function is implemented in
+`pkgs/development/interpreters/python/build-python-package.nix`
+
+The following is an example:
+```nix
+{ lib, buildPythonPackage, fetchPypi, hypothesis, setuptools_scm, attrs, py, setuptools, six, pluggy }:
+
+buildPythonPackage rec {
+  pname = "pytest";
+  version = "3.3.1";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "cf8436dc59d8695346fcd3ab296de46425ecab00d64096cebe79fb51ecb2eb93";
+  };
+
+  postPatch = ''
+    # don't test bash builtins
+    rm testing/test_argcomplete.py
+  '';
+
+  checkInputs = [ hypothesis ];
+  buildInputs = [ setuptools_scm ];
+  propagatedBuildInputs = [ attrs py setuptools six pluggy ];
+
+  meta = with lib; {
+    maintainers = with maintainers; [ domenkozar lovek323 madjar lsix ];
+    description = "Framework for writing tests";
+  };
+}
+```
+
+The `buildPythonPackage` mainly does four things:
+
+* In the `buildPhase`, it calls `${python.interpreter} setup.py bdist_wheel` to
+  build a wheel binary zipfile.
+* In the `installPhase`, it installs the wheel file using `pip install *.whl`.
+* In the `postFixup` phase, the `wrapPythonPrograms` bash function is called to
+  wrap all programs in the `$out/bin/*` directory to include `$PATH`
+  environment variable and add dependent libraries to script's `sys.path`.
+* In the `installCheck` phase, `${python.interpreter} setup.py test` is ran.
+
+As in Perl, dependencies on other Python packages can be specified in the
+`buildInputs` and `propagatedBuildInputs` attributes.  If something is
+exclusively a build-time dependency, use `buildInputs`; if it is (also) a runtime
+dependency, use `propagatedBuildInputs`.
+
+By default tests are run because `doCheck = true`. Test dependencies, like
+e.g. the test runner, should be added to `checkInputs`.
+
+By default `meta.platforms` is set to the same value
+as the interpreter unless overridden otherwise.
+
+##### `buildPythonPackage` parameters
+
+All parameters from `stdenv.mkDerivation` function are still supported. The following are specific to `buildPythonPackage`:
+
+* `catchConflicts ? true`: If `true`, abort package build if a package name appears more than once in dependency tree. Default is `true`.
+* `checkInputs ? []`: Dependencies needed for running the `checkPhase`. These are added to `buildInputs` when `doCheck = true`.
+* `disabled` ? false: If `true`, package is not build for the particular Python interpreter version.
+* `dontWrapPythonPrograms ? false`: Skip wrapping of python programs.
+* `installFlags ? []`: A list of strings. Arguments to be passed to `pip install`. To pass options to `python setup.py install`, use `--install-option`. E.g., `installFlags=["--install-option='--cpp_implementation'"].
+* `format ? "setuptools"`: Format of the source. Valid options are `"setuptools"`, `"flit"`, `"wheel"`, and `"other"`. `"setuptools"` is for when the source has a `setup.py` and `setuptools` is used to build a wheel, `flit`, in case `flit` should be used to build a wheel, and `wheel` in case a wheel is provided. Use `other` when a custom `buildPhase` and/or `installPhase` is needed.
+* `makeWrapperArgs ? []`: A list of strings. Arguments to be passed to `makeWrapper`, which wraps generated binaries. By default, the arguments to `makeWrapper` set `PATH` and `PYTHONPATH` environment variables before calling the binary. Additional arguments here can allow a developer to set environment variables which will be available when the binary is run. For example, `makeWrapperArgs = ["--set FOO BAR" "--set BAZ QUX"]`.
+* `namePrefix`: Prepends text to `${name}` parameter. In case of libraries, this defaults to `"python3.5-"` for Python 3.5, etc., and in case of applications to `""`.
+* `pythonPath ? []`: List of packages to be added into `$PYTHONPATH`. Packages in `pythonPath` are not propagated (contrary to `propagatedBuildInputs`).
+* `preShellHook`: Hook to execute commands before `shellHook`.
+* `postShellHook`: Hook to execute commands after `shellHook`.
+* `removeBinByteCode ? true`: Remove bytecode from `/bin`. Bytecode is only created when the filenames end with `.py`.
+* `setupPyBuildFlags ? []`: List of flags passed to `setup.py build_ext` command.
+
+##### Overriding Python packages
+
+The `buildPythonPackage` function has a `overridePythonAttrs` method that
+can be used to override the package. In the following example we create an
+environment where we have the `blaze` package using an older version of `pandas`.
+We override first the Python interpreter and pass
+`packageOverrides` which contains the overrides for packages in the package set.
+
+```nix
+with import <nixpkgs> {};
+
+(let
+  python = let
+    packageOverrides = self: super: {
+      pandas = super.pandas.overridePythonAttrs(old: rec {
+        version = "0.19.1";
+        src =  super.fetchPypi {
+          pname = "pandas";
+          inherit version;
+          sha256 = "08blshqj9zj1wyjhhw3kl2vas75vhhicvv72flvf1z3jvapgw295";
+        };
+      });
+    };
+  in pkgs.python3.override {inherit packageOverrides;};
+
+in python.withPackages(ps: [ps.blaze])).env
+```
+
+#### `buildPythonApplication` function
+
+The `buildPythonApplication` function is practically the same as
+`buildPythonPackage`. The main purpose of this function is to build a Python
+package where one is interested only in the executables, and not importable
+modules. For that reason, when adding this package to a `python.buildEnv`, the
+modules won't be made available.
+
+Another difference is that `buildPythonPackage` by default prefixes the names of
+the packages with the version of the interpreter. Because this is irrelevant for
+applications, the prefix is omitted.
+
+When packaging a python application with `buildPythonApplication`, it should be
+called with `callPackage` and passed `python` or `pythonPackages` (possibly
+specifying an interpreter version), like this:
+
+```nix
+{ lib, python3Packages }:
+
+python3Packages.buildPythonApplication rec {
+  pname = "luigi";
+  version = "2.7.9";
+
+  src = python3Packages.fetchPypi {
+    inherit pname version;
+    sha256 = "035w8gqql36zlan0xjrzz9j4lh9hs0qrsgnbyw07qs7lnkvbdv9x";
+  };
+
+  propagatedBuildInputs = with python3Packages; [ tornado_4 python-daemon ];
+
+  meta = with lib; {
+    ...
+  };
+}
+```
+
+This is then added to `all-packages.nix` just as any other application would be.
+
+```nix
+luigi = callPackage ../applications/networking/cluster/luigi { };
+```
+
+Since the package is an application, a consumer doesn't need to care about
+python versions or modules, which is why they don't go in `pythonPackages`.
+
+#### `toPythonApplication` function
+
+A distinction is made between applications and libraries, however, sometimes a
+package is used as both. In this case the package is added as a library to
+`python-packages.nix` and as an application to `all-packages.nix`. To reduce
+duplication the `toPythonApplication` can be used to convert a library to an
+application.
+
+The Nix expression shall use `buildPythonPackage` and be called from
+`python-packages.nix`. A reference shall be created from `all-packages.nix` to
+the attribute in `python-packages.nix`, and the `toPythonApplication` shall be
+applied to the reference:
+```nix
+youtube-dl = with pythonPackages; toPythonApplication youtube-dl;
+```
+
+#### `toPythonModule` function
+
+In some cases, such as bindings, a package is created using
+`stdenv.mkDerivation` and added as attribute in `all-packages.nix`.
+The Python bindings should be made available from `python-packages.nix`.
+The `toPythonModule` function takes a derivation and makes certain Python-specific modifications.
+```nix
+opencv = toPythonModule (pkgs.opencv.override {
+  enablePython = true;
+  pythonPackages = self;
+});
+```
+Do pay attention to passing in the right Python version!
+
+#### `python.buildEnv` function
+
+Python environments can be created using the low-level `pkgs.buildEnv` function.
+This example shows how to create an environment that has the Pyramid Web Framework.
+Saving the following as `default.nix`
+```nix
+with import <nixpkgs> {};
+
+python.buildEnv.override {
+  extraLibs = [ pkgs.pythonPackages.pyramid ];
+  ignoreCollisions = true;
+}
+```
+
+and running `nix-build` will create
+```
+/nix/store/cf1xhjwzmdki7fasgr4kz6di72ykicl5-python-2.7.8-env
+```
+
+with wrapped binaries in `bin/`.
+
+You can also use the `env` attribute to create local environments with needed
+packages installed. This is somewhat comparable to `virtualenv`. For example,
+running `nix-shell` with the following `shell.nix`
+```nix
+with import <nixpkgs> {};
+
+(python3.buildEnv.override {
+  extraLibs = with python3Packages; [ numpy requests ];
+}).env
+```
+
+will drop you into a shell where Python will have the
+specified packages in its path.
+
+
+##### `python.buildEnv` arguments
+
+* `extraLibs`: List of packages installed inside the environment.
+* `postBuild`: Shell command executed after the build of environment.
+* `ignoreCollisions`: Ignore file collisions inside the environment (default is `false`).
+
+#### `python.withPackages` function
+
+The `python.withPackages` function provides a simpler interface to the `python.buildEnv` functionality.
+It takes a function as an argument that is passed the set of python packages and returns the list
+of the packages to be included in the environment. Using the `withPackages` function, the previous
+example for the Pyramid Web Framework environment can be written like this:
+```nix
+with import <nixpkgs> {};
+
+python.withPackages (ps: [ps.pyramid])
+```
+
+`withPackages` passes the correct package set for the specific interpreter version as an
+argument to the function. In the above example, `ps` equals `pythonPackages`.
+But you can also easily switch to using python3:
+```nix
+with import <nixpkgs> {};
+
+python3.withPackages (ps: [ps.pyramid])
+```
+
+Now, `ps` is set to `python3Packages`, matching the version of the interpreter.
+
+As `python.withPackages` simply uses `python.buildEnv` under the hood, it also supports the `env`
+attribute. The `shell.nix` file from the previous section can thus be also written like this:
+```nix
+with import <nixpkgs> {};
+
+(python36.withPackages (ps: [ps.numpy ps.requests])).env
+```
+
+In contrast to `python.buildEnv`, `python.withPackages` does not support the more advanced options
+such as `ignoreCollisions = true` or `postBuild`. If you need them, you have to use `python.buildEnv`.
+
+Python 2 namespace packages may provide `__init__.py` that collide. In that case `python.buildEnv`
+should be used with `ignoreCollisions = true`.
+
+### Development mode
+
+Development or editable mode is supported. To develop Python packages
+`buildPythonPackage` has additional logic inside `shellPhase` to run `pip
+install -e . --prefix $TMPDIR/`for the package.
+
+Warning: `shellPhase` is executed only if `setup.py` exists.
+
+Given a `default.nix`:
+```nix
+with import <nixpkgs> {};
+
+buildPythonPackage { name = "myproject";
+
+buildInputs = with pkgs.pythonPackages; [ pyramid ];
+
+src = ./.; }
+```
+
+Running `nix-shell` with no arguments should give you
+the environment in which the package would be built with
+`nix-build`.
+
+Shortcut to setup environments with C headers/libraries and python packages:
+```shell
+nix-shell -p pythonPackages.pyramid zlib libjpeg git
+```
+
+Note: There is a boolean value `lib.inNixShell` set to `true` if nix-shell is invoked.
+
+### Tools
+
+Packages inside nixpkgs are written by hand. However many tools exist in
+community to help save time. No tool is preferred at the moment.
+
+- [python2nix](https://github.com/proger/python2nix) by Vladimir Kirillov
+- [pypi2nix](https://github.com/garbas/pypi2nix) by Rok Garbas
+- [pypi2nix](https://github.com/offlinehacker/pypi2nix) by Jaka Hudoklin
+
+### Deterministic builds
+
+The Python interpreters are now built deterministically.
+Minor modifications had to be made to the interpreters in order to generate
+deterministic bytecode. This has security implications and is relevant for
+those using Python in a `nix-shell`.
+
+When the environment variable `DETERMINISTIC_BUILD` is set, all bytecode will have timestamp 1.
+The `buildPythonPackage` function sets `DETERMINISTIC_BUILD=1` and
+[PYTHONHASHSEED=0](https://docs.python.org/3.5/using/cmdline.html#envvar-PYTHONHASHSEED).
+Both are also exported in `nix-shell`.
+
+
+### Automatic tests
+
+It is recommended to test packages as part of the build process.
+Source distributions (`sdist`) often include test files, but not always.
+
+By default the command `python setup.py test` is run as part of the
+`checkPhase`, but often it is necessary to pass a custom `checkPhase`. An
+example of such a situation is when `py.test` is used.
+
+#### Common issues
+
+- Non-working tests can often be deselected. By default `buildPythonPackage` runs `python setup.py test`.
+  Most python modules follows the standard test protocol where the pytest runner can be used instead.
+  `py.test` supports a `-k` parameter to ignore test methods or classes:
+
+  ```nix
+  buildPythonPackage {
+    # ...
+    # assumes the tests are located in tests
+    checkInputs = [ pytest ];
+    checkPhase = ''
+      py.test -k 'not function_name and not other_function' tests
+    '';
+  }
+  ```
+- Unicode issues can typically be fixed by including `glibcLocales` in `buildInputs` and exporting `LC_ALL=en_US.utf-8`.
+- Tests that attempt to access `$HOME` can be fixed by using the following work-around before running tests (e.g. `preCheck`): `export HOME=$(mktemp -d)`
+
+## FAQ
+
+### How to solve circular dependencies?
+
+Consider the packages `A` and `B` that depend on each other. When packaging `B`,
+a solution is to override package `A` not to depend on `B` as an input. The same
+should also be done when packaging `A`.
+
+### How to override a Python package?
+
+We can override the interpreter and pass `packageOverrides`.
+In the following example we rename the `pandas` package and build it.
+```nix
+with import <nixpkgs> {};
+
+(let
+  python = let
+    packageOverrides = self: super: {
+      pandas = super.pandas.overridePythonAttrs(old: {name="foo";});
+    };
+  in pkgs.python35.override {inherit packageOverrides;};
+
+in python.withPackages(ps: [ps.pandas])).env
+```
+Using `nix-build` on this expression will build an environment that contains the
+package `pandas` but with the new name `foo`.
+
+All packages in the package set will use the renamed package.
+A typical use case is to switch to another version of a certain package.
+For example, in the Nixpkgs repository we have multiple versions of `django` and `scipy`.
+In the following example we use a different version of `scipy` and create an environment that uses it.
+All packages in the Python package set will now use the updated `scipy` version.
+
+```nix
+with import <nixpkgs> {};
+
+( let
+    packageOverrides = self: super: {
+      scipy = super.scipy_0_17;
+    };
+  in (pkgs.python35.override {inherit packageOverrides;}).withPackages (ps: [ps.blaze])
+).env
+```
+The requested package `blaze` depends on `pandas` which itself depends on `scipy`.
+
+If you want the whole of Nixpkgs to use your modifications, then you can use `overlays`
+as explained in this manual. In the following example we build a `inkscape` using a different version of `numpy`.
+```nix
+let
+  pkgs = import <nixpkgs> {};
+  newpkgs = import pkgs.path { overlays = [ (pkgsself: pkgssuper: {
+    python27 = let
+      packageOverrides = self: super: {
+        numpy = super.numpy_1_10;
+      };
+    in pkgssuper.python27.override {inherit packageOverrides;};
+  } ) ]; };
+in newpkgs.inkscape
+```
+
+### `python setup.py bdist_wheel` cannot create .whl
+
+Executing `python setup.py bdist_wheel` in a `nix-shell `fails with
+```
+ValueError: ZIP does not support timestamps before 1980
+```
+
+This is because files from the Nix store (which have a timestamp of the UNIX epoch of January 1, 1970) are included in the .ZIP, but .ZIP archives follow the DOS convention of counting timestamps from 1980.
+
+The command `bdist_wheel` reads the `SOURCE_DATE_EPOCH` environment variable, which `nix-shell` sets to 1. Unsetting this variable or giving it a value corresponding to 1980 or later enables building wheels.
+
+Use 1980 as timestamp:
+```shell
+nix-shell --run "SOURCE_DATE_EPOCH=315532800 python3 setup.py bdist_wheel"
+```
+or the current time:
+```shell
+nix-shell --run "SOURCE_DATE_EPOCH=$(date +%s) python3 setup.py bdist_wheel"
+```
+or unset `SOURCE_DATE_EPOCH`:
+```shell
+nix-shell --run "unset SOURCE_DATE_EPOCH; python3 setup.py bdist_wheel"
+```
+
+### `install_data` / `data_files` problems
+
+If you get the following error:
+```
+could not create '/nix/store/6l1bvljpy8gazlsw2aw9skwwp4pmvyxw-python-2.7.8/etc':
+Permission denied
+```
+This is a [known bug](https://github.com/pypa/setuptools/issues/130) in `setuptools`.
+Setuptools `install_data` does not respect `--prefix`. An example of such package using the feature is `pkgs/tools/X11/xpra/default.nix`.
+As workaround install it as an extra `preInstall` step:
+```shell
+${python.interpreter} setup.py install_data --install-dir=$out --root=$out
+sed -i '/ = data\_files/d' setup.py
+```
+
+###  Rationale of non-existent global site-packages
+
+On most operating systems a global `site-packages` is maintained. This however
+becomes problematic if you want to run multiple Python versions or have multiple
+versions of certain libraries for your projects. Generally, you would solve such
+issues by creating virtual environments using `virtualenv`.
+
+On Nix each package has an isolated dependency tree which, in the case of
+Python, guarantees the right versions of the interpreter and libraries or
+packages are available. There is therefore no need to maintain a global `site-packages`.
+
+If you want to create a Python environment for development, then the recommended
+method is to use `nix-shell`, either with or without the `python.buildEnv`
+function.
+
+### How to consume python modules using pip in a virtualenv like I am used to on other Operating Systems ?
+
+This is an example of a `default.nix` for a `nix-shell`, which allows to consume a `virtualenv` environment,
+and install python modules through `pip` the traditional way.
+
+Create this `default.nix` file, together with a `requirements.txt` and simply execute `nix-shell`.
+
+```nix
+with import <nixpkgs> {};
+with pkgs.python27Packages;
+
+stdenv.mkDerivation {
+  name = "impurePythonEnv";
+  buildInputs = [
+    # these packages are required for virtualenv and pip to work:
+    #
+    python27Full
+    python27Packages.virtualenv
+    python27Packages.pip
+    # the following packages are related to the dependencies of your python
+    # project.
+    # In this particular example the python modules listed in the
+    # requirements.txt require the following packages to be installed locally
+    # in order to compile any binary extensions they may require.
+    #
+    taglib
+    openssl
+    git
+    libxml2
+    libxslt
+    libzip
+    stdenv
+    zlib ];
+  src = null;
+  shellHook = ''
+  # set SOURCE_DATE_EPOCH so that we can use python wheels
+  SOURCE_DATE_EPOCH=$(date +%s)
+  virtualenv --no-setuptools venv
+  export PATH=$PWD/venv/bin:$PATH
+  pip install -r requirements.txt
+  '';
+}
+```
+
+Note that the `pip install` is an imperative action. So every time `nix-shell`
+is executed it will attempt to download the python modules listed in
+requirements.txt. However these will be cached locally within the `virtualenv`
+folder and not downloaded again.
+
+### How to override a Python package from `configuration.nix`?
+
+If you need to change a package's attribute(s) from `configuration.nix` you could do:
+
+```nix
+  nixpkgs.config.packageOverrides = super: {
+    python = super.python.override {
+      packageOverrides = python-self: python-super: {
+        zerobin = python-super.zerobin.overrideAttrs (oldAttrs: {
+          src = super.fetchgit {
+            url = "https://github.com/sametmax/0bin";
+            rev = "a344dbb18fe7a855d0742b9a1cede7ce423b34ec";
+            sha256 = "16d769kmnrpbdr0ph0whyf4yff5df6zi4kmwx7sz1d3r6c8p6xji";
+          };
+        });
+      };
+    };
+  };
+```
+
+`pythonPackages.zerobin` is now globally overridden. All packages and also the
+`zerobin` NixOS service use the new definition.
+Note that `python-super` refers to the old package set and `python-self`
+to the new, overridden version.
+
+To modify only a Python package set instead of a whole Python derivation, use this snippet:
+
+```nix
+  myPythonPackages = pythonPackages.override {
+    overrides = self: super: {
+      zerobin = ...;
+    };
+  }
+```
+
+### How to override a Python package using overlays?
+
+Use the following overlay template:
+
+```nix
+self: super: {
+  python = super.python.override {
+    packageOverrides = python-self: python-super: {
+      zerobin = python-super.zerobin.overrideAttrs (oldAttrs: {
+        src = super.fetchgit {
+          url = "https://github.com/sametmax/0bin";
+          rev = "a344dbb18fe7a855d0742b9a1cede7ce423b34ec";
+          sha256 = "16d769kmnrpbdr0ph0whyf4yff5df6zi4kmwx7sz1d3r6c8p6xji";
+        };
+      });
+    };
+  };
+}
+```
+
+### How to use Intel's MKL with numpy and scipy?
+
+A `site.cfg` is created that configures BLAS based on the `blas` parameter
+of the `numpy` derivation. By passing in `mkl`, `numpy` and packages depending
+on `numpy` will be built with `mkl`.
+
+The following is an overlay that configures `numpy` to use `mkl`:
+```nix
+self: super: {
+  python37 = super.python37.override {
+    packageOverrides = python-self: python-super: {
+      numpy = python-super.numpy.override {
+        blas = super.pkgs.mkl;
+      };
+    };
+  };
+}
+```
+
+`mkl` requires an `openmp` implementation when running with multiple processors.
+By default, `mkl` will use Intel's `iomp` implementation if no other is
+specified, but this is a runtime-only dependency and binary compatible with the
+LLVM implementation. To use that one instead, Intel recommends users set it with
+`LD_PRELOAD`.
+
+Note that `mkl` is only available on `x86_64-{linux,darwin}` platforms;
+moreover, Hydra is not building and distributing pre-compiled binaries using it.
+
+## Contributing
+
+### Contributing guidelines
+
+Following rules are desired to be respected:
+
+* Python libraries are called from `python-packages.nix` and packaged with `buildPythonPackage`. The expression of a library should be in `pkgs/development/python-modules/<name>/default.nix`. Libraries in `pkgs/top-level/python-packages.nix` are sorted quasi-alphabetically to avoid merge conflicts.
+* Python applications live outside of `python-packages.nix` and are packaged with `buildPythonApplication`.
+* Make sure libraries build for all Python interpreters.
+* By default we enable tests. Make sure the tests are found and, in the case of libraries, are passing for all interpreters. If certain tests fail they can be disabled individually. Try to avoid disabling the tests altogether. In any case, when you disable tests, leave a comment explaining why.
+* Commit names of Python libraries should reflect that they are Python libraries, so write for example `pythonPackages.numpy: 1.11 -> 1.12`.
+* Attribute names in `python-packages.nix` should be normalized according to [PEP 0503](https://www.python.org/dev/peps/pep-0503/#normalized-names).
+  This means that characters should be converted to lowercase and `.` and `_` should be replaced by a single `-` (foo-bar-baz instead of Foo__Bar.baz )
diff --git a/nixpkgs/doc/languages-frameworks/qt.xml b/nixpkgs/doc/languages-frameworks/qt.xml
new file mode 100644
index 000000000000..b9b605b81da1
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/qt.xml
@@ -0,0 +1,74 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-qt">
+ <title>Qt</title>
+
+ <para>
+  Qt is a comprehensive desktop and mobile application development toolkit for
+  C++. Legacy support is available for Qt 3 and Qt 4, but all current
+  development uses Qt 5. The Qt 5 packages in Nixpkgs are updated frequently to
+  take advantage of new features, but older versions are typically retained
+  until their support window ends. The most important consideration in
+  packaging Qt-based software is ensuring that each package and all its
+  dependencies use the same version of Qt 5; this consideration motivates most
+  of the tools described below.
+ </para>
+
+ <section xml:id="ssec-qt-libraries">
+  <title>Packaging Libraries for Nixpkgs</title>
+
+  <para>
+   Whenever possible, libraries that use Qt 5 should be built with each
+   available version. Packages providing libraries should be added to the
+   top-level function <varname>mkLibsForQt5</varname>, which is used to build a
+   set of libraries for every Qt 5 version. A special
+   <varname>callPackage</varname> function is used in this scope to ensure that
+   the entire dependency tree uses the same Qt 5 version. Import dependencies
+   unqualified, i.e., <literal>qtbase</literal> not
+   <literal>qt5.qtbase</literal>. <emphasis>Do not</emphasis> import a package
+   set such as <literal>qt5</literal> or <literal>libsForQt5</literal>.
+  </para>
+
+  <para>
+   If a library does not support a particular version of Qt 5, it is best to
+   mark it as broken by setting its <literal>meta.broken</literal> attribute. A
+   package may be marked broken for certain versions by testing the
+   <literal>qtbase.version</literal> attribute, which will always give the
+   current Qt 5 version.
+  </para>
+ </section>
+
+ <section xml:id="ssec-qt-applications">
+  <title>Packaging Applications for Nixpkgs</title>
+
+  <para>
+   Call your application expression using
+   <literal>libsForQt5.callPackage</literal> instead of
+   <literal>callPackage</literal>. Import dependencies unqualified, i.e.,
+   <literal>qtbase</literal> not <literal>qt5.qtbase</literal>. <emphasis>Do
+   not</emphasis> import a package set such as <literal>qt5</literal> or
+   <literal>libsForQt5</literal>.
+  </para>
+
+  <para>
+   Qt 5 maintains strict backward compatibility, so it is generally best to
+   build an application package against the latest version using the
+   <varname>libsForQt5</varname> library set. In case a package does not build
+   with the latest Qt version, it is possible to pick a set pinned to a
+   particular version, e.g. <varname>libsForQt55</varname> for Qt 5.5, if that
+   is the latest version the package supports. If a package must be pinned to
+   an older Qt version, be sure to file a bug upstream; because Qt is strictly
+   backwards-compatible, any incompatibility is by definition a bug in the
+   application.
+  </para>
+
+  <para>
+   When testing applications in Nixpkgs, it is a common practice to build the
+   package with <literal>nix-build</literal> and run it using the created
+   symbolic link. This will not work with Qt applications, however, because
+   they have many hard runtime requirements that can only be guaranteed if the
+   package is actually installed. To test a Qt application, install it with
+   <literal>nix-env</literal> or run it inside <literal>nix-shell</literal>.
+  </para>
+ </section>
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/r.section.md b/nixpkgs/doc/languages-frameworks/r.section.md
new file mode 100644
index 000000000000..c8f02bd14780
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/r.section.md
@@ -0,0 +1,120 @@
+R packages
+==========
+
+## Installation
+
+Define an environment for R that contains all the libraries that you'd like to
+use by adding the following snippet to your $HOME/.config/nixpkgs/config.nix file:
+
+```nix
+{
+    packageOverrides = super: let self = super.pkgs; in
+    {
+
+        rEnv = super.rWrapper.override {
+            packages = with self.rPackages; [
+                devtools
+                ggplot2
+                reshape2
+                yaml
+                optparse
+                ];
+        };
+    };
+}
+```
+
+Then you can use `nix-env -f "<nixpkgs>" -iA rEnv` to install it into your user
+profile. The set of available libraries can be discovered by running the
+command `nix-env -f "<nixpkgs>" -qaP -A rPackages`. The first column from that
+output is the name that has to be passed to rWrapper in the code snipped above.
+
+However, if you'd like to add a file to your project source to make the
+environment available for other contributors, you can create a `default.nix`
+file like so:
+```nix
+let
+  pkgs = import <nixpkgs> {};
+  stdenv = pkgs.stdenv;
+in with pkgs; {
+  myProject = stdenv.mkDerivation {
+    name = "myProject";
+    version = "1";
+    src = if pkgs.lib.inNixShell then null else nix;
+
+    buildInputs = with rPackages; [
+      R
+      ggplot2
+      knitr
+    ];
+  };
+}
+```
+and then run `nix-shell .` to be dropped into a shell with those packages
+available.
+
+## RStudio
+
+RStudio uses a standard set of packages and ignores any custom R
+environments or installed packages you may have.  To create a custom
+environment, see `rstudioWrapper`, which functions similarly to
+`rWrapper`:
+
+```nix
+{
+    packageOverrides = super: let self = super.pkgs; in
+    {
+
+        rstudioEnv = super.rstudioWrapper.override {
+            packages = with self.rPackages; [
+                dplyr
+                ggplot2
+                reshape2
+                ];
+        };
+    };
+}
+```
+
+Then like above, `nix-env -f "<nixpkgs>" -iA rstudioEnv` will install
+this into your user profile.
+
+Alternatively, you can create a self-contained `shell.nix` without the need to
+modify any configuration files:
+
+```nix
+{ pkgs ? import <nixpkgs> {}
+}:
+
+pkgs.rstudioWrapper.override {
+  packages = with pkgs.rPackages; [ dplyr ggplot2 reshape2 ];
+}
+
+```
+
+Executing `nix-shell` will then drop you into an environment equivalent to the
+one above. If you need additional packages just add them to the list and
+re-enter the shell.
+
+## Updating the package set
+
+```bash
+nix-shell generate-shell.nix
+
+Rscript generate-r-packages.R cran  > cran-packages.nix.new
+mv cran-packages.nix.new cran-packages.nix
+
+Rscript generate-r-packages.R bioc  > bioc-packages.nix.new
+mv bioc-packages.nix.new bioc-packages.nix
+```
+
+`generate-r-packages.R <repo>` reads  `<repo>-packages.nix`, therefor the renaming.
+
+
+## Testing if the Nix-expression could be evaluated
+
+```bash
+nix-build test-evaluation.nix --dry-run
+```
+
+If this exits fine, the expression is ok. If not, you have to edit `default.nix`
diff --git a/nixpkgs/doc/languages-frameworks/ruby.xml b/nixpkgs/doc/languages-frameworks/ruby.xml
new file mode 100644
index 000000000000..df4e5acb22cb
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/ruby.xml
@@ -0,0 +1,135 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-ruby">
+ <title>Ruby</title>
+
+ <para>
+  There currently is support to bundle applications that are packaged as Ruby
+  gems. The utility "bundix" allows you to write a
+  <filename>Gemfile</filename>, let bundler create a
+  <filename>Gemfile.lock</filename>, and then convert this into a nix
+  expression that contains all Gem dependencies automatically.
+ </para>
+
+ <para>
+  For example, to package sensu, we did:
+ </para>
+
+<screen>
+<![CDATA[$ cd pkgs/servers/monitoring
+$ mkdir sensu
+$ cd sensu
+$ cat > Gemfile
+source 'https://rubygems.org'
+gem 'sensu'
+$ $(nix-build '<nixpkgs>' -A bundix --no-out-link)/bin/bundix --magic
+$ cat > default.nix
+{ lib, bundlerEnv, ruby }:
+
+bundlerEnv rec {
+  name = "sensu-${version}";
+
+  version = (import gemset).sensu.version;
+  inherit ruby;
+  # expects Gemfile, Gemfile.lock and gemset.nix in the same directory
+  gemdir = ./.;
+
+  meta = with lib; {
+    description = "A monitoring framework that aims to be simple, malleable, and scalable";
+    homepage    = http://sensuapp.org/;
+    license     = with licenses; mit;
+    maintainers = with maintainers; [ theuni ];
+    platforms   = platforms.unix;
+  };
+}]]>
+</screen>
+
+ <para>
+  Please check in the <filename>Gemfile</filename>,
+  <filename>Gemfile.lock</filename> and the <filename>gemset.nix</filename> so
+  future updates can be run easily.
+ </para>
+
+ <para>
+  Updating Ruby packages can then be done like this:
+ </para>
+
+<screen>
+<![CDATA[$ cd pkgs/servers/monitoring/sensu
+$ nix-shell -p bundler --run 'bundle lock --update'
+$ nix-shell -p bundix --run 'bundix'
+]]>
+</screen>
+
+ <para>
+  For tools written in Ruby - i.e. where the desire is to install a package and
+  then execute e.g. <command>rake</command> at the command line, there is an
+  alternative builder called <literal>bundlerApp</literal>. Set up the
+  <filename>gemset.nix</filename> the same way, and then, for example:
+ </para>
+
+<screen>
+<![CDATA[{ lib, bundlerApp }:
+
+bundlerApp {
+  pname = "corundum";
+  gemdir = ./.;
+  exes = [ "corundum-skel" ];
+
+  meta = with lib; {
+    description = "Tool and libraries for maintaining Ruby gems.";
+    homepage    = https://github.com/nyarly/corundum;
+    license     = licenses.mit;
+    maintainers = [ maintainers.nyarly ];
+    platforms   = platforms.unix;
+  };
+}]]>
+</screen>
+
+ <para>
+  The chief advantage of <literal>bundlerApp</literal> over
+  <literal>bundlerEnv</literal> is the executables introduced in the
+  environment are precisely those selected in the <literal>exes</literal> list,
+  as opposed to <literal>bundlerEnv</literal> which adds all the executables
+  made available by gems in the gemset, which can mean e.g.
+  <command>rspec</command> or <command>rake</command> in unpredictable versions
+  available from various packages.
+ </para>
+
+ <para>
+  Resulting derivations for both builders also have two helpful attributes,
+  <literal>env</literal> and <literal>wrappedRuby</literal>. The first one
+  allows one to quickly drop into <command>nix-shell</command> with the
+  specified environment present. E.g. <command>nix-shell -A sensu.env</command>
+  would give you an environment with Ruby preset so it has all the libraries
+  necessary for <literal>sensu</literal> in its paths. The second one can be
+  used to make derivations from custom Ruby scripts which have
+  <filename>Gemfile</filename>s with their dependencies specified. It is a
+  derivation with <command>ruby</command> wrapped so it can find all the needed
+  dependencies. For example, to make a derivation <literal>my-script</literal>
+  for a <filename>my-script.rb</filename> (which should be placed in
+  <filename>bin</filename>) you should run <command>bundix</command> as
+  specified above and then use <literal>bundlerEnv</literal> like this:
+ </para>
+
+<programlisting>
+<![CDATA[let env = bundlerEnv {
+  name = "my-script-env";
+
+  inherit ruby;
+  gemfile = ./Gemfile;
+  lockfile = ./Gemfile.lock;
+  gemset = ./gemset.nix;
+};
+
+in stdenv.mkDerivation {
+  name = "my-script";
+  buildInputs = [ env.wrappedRuby ];
+  script = ./my-script.rb;
+  buildCommand = ''
+    install -D -m755 $script $out/bin/my-script
+    patchShebangs $out/bin/my-script
+  '';
+}]]>
+</programlisting>
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/rust.section.md b/nixpkgs/doc/languages-frameworks/rust.section.md
new file mode 100644
index 000000000000..4549bbd1686b
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/rust.section.md
@@ -0,0 +1,395 @@
+---
+title: Rust
+author: Matthias Beyer
+date: 2017-03-05
+---
+
+# User's Guide to the Rust Infrastructure
+
+To install the rust compiler and cargo put
+
+```
+rustc
+cargo
+```
+
+into the `environment.systemPackages` or bring them into
+scope with `nix-shell -p rustc cargo`.
+
+> If you are using NixOS and you want to use rust without a nix expression you
+> probably want to add the following in your `configuration.nix` to build
+> crates with C dependencies.
+>
+>     environment.systemPackages = [binutils gcc gnumake openssl pkgconfig]
+
+For daily builds (beta and nightly) use either rustup from
+nixpkgs or use the [Rust nightlies
+overlay](#using-the-rust-nightlies-overlay).
+
+## Compiling Rust applications with Cargo
+
+Rust applications are packaged by using the `buildRustPackage` helper from `rustPlatform`:
+
+```
+rustPlatform.buildRustPackage rec {
+  name = "ripgrep-${version}";
+  version = "0.4.0";
+
+  src = fetchFromGitHub {
+    owner = "BurntSushi";
+    repo = "ripgrep";
+    rev = "${version}";
+    sha256 = "0y5d1n6hkw85jb3rblcxqas2fp82h3nghssa4xqrhqnz25l799pj";
+  };
+
+  cargoSha256 = "0q68qyl2h6i0qsz82z840myxlnjay8p1w5z7hfyr8fqp7wgwa9cx";
+
+  meta = with stdenv.lib; {
+    description = "A fast line-oriented regex search tool, similar to ag and ack";
+    homepage = https://github.com/BurntSushi/ripgrep;
+    license = licenses.unlicense;
+    maintainers = [ maintainers.tailhook ];
+    platforms = platforms.all;
+  };
+}
+```
+
+`buildRustPackage` requires a `cargoSha256` attribute which is computed over
+all crate sources of this package. Currently it is obtained by inserting a
+fake checksum into the expression and building the package once. The correct
+checksum can be then take from the failed build.
+
+When the `Cargo.lock`, provided by upstream, is not in sync with the
+`Cargo.toml`, it is possible to use `cargoPatches` to update it. All patches
+added in `cargoPatches` will also be prepended to the patches in `patches` at
+build-time.
+
+## Compiling Rust crates using Nix instead of Cargo
+
+### Simple operation
+
+When run, `cargo build` produces a file called `Cargo.lock`,
+containing pinned versions of all dependencies. Nixpkgs contains a
+tool called `carnix` (`nix-env -iA nixos.carnix`), which can be used
+to turn a `Cargo.lock` into a Nix expression.
+
+That Nix expression calls `rustc` directly (hence bypassing Cargo),
+and can be used to compile a crate and all its dependencies. Here is
+an example for a minimal `hello` crate:
+
+
+    $ cargo new hello
+    $ cd hello
+    $ cargo build
+     Compiling hello v0.1.0 (file:///tmp/hello)
+      Finished dev [unoptimized + debuginfo] target(s) in 0.20 secs
+    $ carnix -o hello.nix --src ./. Cargo.lock --standalone
+    $ nix-build hello.nix -A hello_0_1_0
+
+Now, the file produced by the call to `carnix`, called `hello.nix`, looks like:
+
+```
+# Generated by carnix 0.6.5: carnix -o hello.nix --src ./. Cargo.lock --standalone
+{ lib, stdenv, buildRustCrate, fetchgit }:
+let kernel = stdenv.buildPlatform.parsed.kernel.name;
+    # ... (content skipped)
+in
+rec {
+  hello = f: hello_0_1_0 { features = hello_0_1_0_features { hello_0_1_0 = f; }; };
+  hello_0_1_0_ = { dependencies?[], buildDependencies?[], features?[] }: buildRustCrate {
+    crateName = "hello";
+    version = "0.1.0";
+    authors = [ "pe@pijul.org <pe@pijul.org>" ];
+    src = ./.;
+    inherit dependencies buildDependencies features;
+  };
+  hello_0_1_0 = { features?(hello_0_1_0_features {}) }: hello_0_1_0_ {};
+  hello_0_1_0_features = f: updateFeatures f (rec {
+        hello_0_1_0.default = (f.hello_0_1_0.default or true);
+    }) [ ];
+}
+```
+
+In particular, note that the argument given as `--src` is copied
+verbatim to the source. If we look at a more complicated
+dependencies, for instance by adding a single line `libc="*"` to our
+`Cargo.toml`, we first need to run `cargo build` to update the
+`Cargo.lock`. Then, `carnix` needs to be run again, and produces the
+following nix file:
+
+```
+# Generated by carnix 0.6.5: carnix -o hello.nix --src ./. Cargo.lock --standalone
+{ lib, stdenv, buildRustCrate, fetchgit }:
+let kernel = stdenv.buildPlatform.parsed.kernel.name;
+    # ... (content skipped)
+in
+rec {
+  hello = f: hello_0_1_0 { features = hello_0_1_0_features { hello_0_1_0 = f; }; };
+  hello_0_1_0_ = { dependencies?[], buildDependencies?[], features?[] }: buildRustCrate {
+    crateName = "hello";
+    version = "0.1.0";
+    authors = [ "pe@pijul.org <pe@pijul.org>" ];
+    src = ./.;
+    inherit dependencies buildDependencies features;
+  };
+  libc_0_2_36_ = { dependencies?[], buildDependencies?[], features?[] }: buildRustCrate {
+    crateName = "libc";
+    version = "0.2.36";
+    authors = [ "The Rust Project Developers" ];
+    sha256 = "01633h4yfqm0s302fm0dlba469bx8y6cs4nqc8bqrmjqxfxn515l";
+    inherit dependencies buildDependencies features;
+  };
+  hello_0_1_0 = { features?(hello_0_1_0_features {}) }: hello_0_1_0_ {
+    dependencies = mapFeatures features ([ libc_0_2_36 ]);
+  };
+  hello_0_1_0_features = f: updateFeatures f (rec {
+    hello_0_1_0.default = (f.hello_0_1_0.default or true);
+    libc_0_2_36.default = true;
+  }) [ libc_0_2_36_features ];
+  libc_0_2_36 = { features?(libc_0_2_36_features {}) }: libc_0_2_36_ {
+    features = mkFeatures (features.libc_0_2_36 or {});
+  };
+  libc_0_2_36_features = f: updateFeatures f (rec {
+    libc_0_2_36.default = (f.libc_0_2_36.default or true);
+    libc_0_2_36.use_std =
+      (f.libc_0_2_36.use_std or false) ||
+      (f.libc_0_2_36.default or false) ||
+      (libc_0_2_36.default or false);
+  }) [];
+}
+```
+
+Here, the `libc` crate has no `src` attribute, so `buildRustCrate`
+will fetch it from [crates.io](https://crates.io). A `sha256`
+attribute is still needed for Nix purity.
+
+### Handling external dependencies
+
+Some crates require external libraries. For crates from
+[crates.io](https://crates.io), such libraries can be specified in
+`defaultCrateOverrides` package in nixpkgs itself.
+
+Starting from that file, one can add more overrides, to add features
+or build inputs by overriding the hello crate in a seperate file.
+
+```
+with import <nixpkgs> {};
+((import ./hello.nix).hello {}).override {
+  crateOverrides = defaultCrateOverrides // {
+    hello = attrs: { buildInputs = [ openssl ]; };
+  };
+}
+```
+
+Here, `crateOverrides` is expected to be a attribute set, where the
+key is the crate name without version number and the value a function.
+The function gets all attributes passed to `buildRustCrate` as first
+argument and returns a set that contains all attribute that should be
+overwritten.
+
+For more complicated cases, such as when parts of the crate's
+derivation depend on the the crate's version, the `attrs` argument of
+the override above can be read, as in the following example, which
+patches the derivation:
+
+```
+with import <nixpkgs> {};
+((import ./hello.nix).hello {}).override {
+  crateOverrides = defaultCrateOverrides // {
+    hello = attrs: lib.optionalAttrs (lib.versionAtLeast attrs.version "1.0")  {
+      postPatch = ''
+        substituteInPlace lib/zoneinfo.rs \
+          --replace "/usr/share/zoneinfo" "${tzdata}/share/zoneinfo"
+      '';
+    };
+  };
+}
+```
+
+Another situation is when we want to override a nested
+dependency. This actually works in the exact same way, since the
+`crateOverrides` parameter is forwarded to the crate's
+dependencies. For instance, to override the build inputs for crate
+`libc` in the example above, where `libc` is a dependency of the main
+crate, we could do:
+
+```
+with import <nixpkgs> {};
+((import hello.nix).hello {}).override {
+  crateOverrides = defaultCrateOverrides // {
+    libc = attrs: { buildInputs = []; };
+  };
+}
+```
+
+### Options and phases configuration
+
+Actually, the overrides introduced in the previous section are more
+general. A number of other parameters can be overridden:
+
+- The version of rustc used to compile the crate:
+
+  ```
+  (hello {}).override { rust = pkgs.rust; };
+  ```
+
+- Whether to build in release mode or debug mode (release mode by
+  default):
+
+  ```
+  (hello {}).override { release = false; };
+  ```
+
+- Whether to print the commands sent to rustc when building
+  (equivalent to `--verbose` in cargo:
+
+  ```
+  (hello {}).override { verbose = false; };
+  ```
+
+- Extra arguments to be passed to `rustc`:
+
+  ```
+  (hello {}).override { extraRustcOpts = "-Z debuginfo=2"; };
+  ```
+
+- Phases, just like in any other derivation, can be specified using
+  the following attributes: `preUnpack`, `postUnpack`, `prePatch`,
+  `patches`, `postPatch`, `preConfigure` (in the case of a Rust crate,
+  this is run before calling the "build" script), `postConfigure`
+  (after the "build" script),`preBuild`, `postBuild`, `preInstall` and
+  `postInstall`. As an example, here is how to create a new module
+  before running the build script:
+
+  ```
+  (hello {}).override {
+    preConfigure = ''
+       echo "pub const PATH=\"${hi.out}\";" >> src/path.rs"
+    '';
+  };
+  ```
+
+### Features
+
+One can also supply features switches. For example, if we want to
+compile `diesel_cli` only with the `postgres` feature, and no default
+features, we would write:
+
+```
+(callPackage ./diesel.nix {}).diesel {
+  default = false;
+  postgres = true;
+}
+```
+
+Where `diesel.nix` is the file generated by Carnix, as explained above.
+
+
+## Setting Up `nix-shell`
+Oftentimes you want to develop code from within `nix-shell`. Unfortunately
+`buildRustCrate` does not support common `nix-shell` operations directly
+(see [this issue](https://github.com/NixOS/nixpkgs/issues/37945))
+so we will use `stdenv.mkDerivation` instead.
+
+Using the example `hello` project above, we want to do the following:
+- Have access to `cargo` and `rustc`
+- Have the `openssl` library available to a crate through it's _normal_
+  compilation mechanism (`pkg-config`).
+
+A typical `shell.nix` might look like:
+
+```
+with import <nixpkgs> {};
+
+stdenv.mkDerivation {
+  name = "rust-env";
+  buildInputs = [
+    rustc cargo
+
+    # Example Additional Dependencies
+    pkgconfig openssl
+  ];
+
+  # Set Environment Variables
+  RUST_BACKTRACE = 1;
+}
+```
+
+You should now be able to run the following:
+```
+$ nix-shell --pure
+$ cargo build
+$ cargo test
+```
+
+### Controlling Rust Version Inside `nix-shell`
+To control your rust version (i.e. use nightly) from within `shell.nix` (or
+other nix expressions) you can use the following `shell.nix`
+
+```
+# Latest Nightly
+with import <nixpkgs> {};
+let src = fetchFromGitHub {
+      owner = "mozilla";
+      repo = "nixpkgs-mozilla";
+      # commit from: 2018-03-27
+      rev = "2945b0b6b2fd19e7d23bac695afd65e320efcebe";
+      sha256 = "034m1dryrzh2lmjvk3c0krgip652dql46w5yfwpvh7gavd3iypyw";
+   };
+in
+with import "${src.out}/rust-overlay.nix" pkgs pkgs;
+stdenv.mkDerivation {
+  name = "rust-env";
+  buildInputs = [
+    # Note: to use use stable, just replace `nightly` with `stable`
+    latest.rustChannels.nightly.rust
+
+    # Add some extra dependencies from `pkgs`
+    pkgconfig openssl
+  ];
+
+  # Set Environment Variables
+  RUST_BACKTRACE = 1;
+}
+```
+
+Now run:
+```
+$ rustc --version
+rustc 1.26.0-nightly (188e693b3 2018-03-26)
+```
+
+To see that you are using nightly.
+
+
+## Using the Rust nightlies overlay
+
+Mozilla provides an overlay for nixpkgs to bring a nightly version of Rust into scope.
+This overlay can _also_ be used to install recent unstable or stable versions
+of Rust, if desired.
+
+To use this overlay, clone
+[nixpkgs-mozilla](https://github.com/mozilla/nixpkgs-mozilla),
+and create a symbolic link to the file
+[rust-overlay.nix](https://github.com/mozilla/nixpkgs-mozilla/blob/master/rust-overlay.nix)
+in the `~/.config/nixpkgs/overlays` directory.
+
+    $ git clone https://github.com/mozilla/nixpkgs-mozilla.git
+    $ mkdir -p ~/.config/nixpkgs/overlays
+    $ ln -s $(pwd)/nixpkgs-mozilla/rust-overlay.nix ~/.config/nixpkgs/overlays/rust-overlay.nix
+
+The latest version can be installed with the following command:
+
+    $ nix-env -Ai nixos.latest.rustChannels.stable.rust
+
+Or using the attribute with nix-shell:
+
+    $ nix-shell -p nixos.latest.rustChannels.stable.rust
+
+To install the beta or nightly channel, "stable" should be substituted by
+"nightly" or "beta", or
+use the function provided by this overlay to pull a version based on a
+build date.
+
+The overlay automatically updates itself as it uses the same source as
+[rustup](https://www.rustup.rs/).
diff --git a/nixpkgs/doc/languages-frameworks/texlive.xml b/nixpkgs/doc/languages-frameworks/texlive.xml
new file mode 100644
index 000000000000..5792a16963a9
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/texlive.xml
@@ -0,0 +1,99 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-language-texlive">
+ <title>TeX Live</title>
+
+ <para>
+  Since release 15.09 there is a new TeX Live packaging that lives entirely
+  under attribute <varname>texlive</varname>.
+ </para>
+
+ <section xml:id="sec-language-texlive-users-guide">
+  <title>User's guide</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     For basic usage just pull <varname>texlive.combined.scheme-basic</varname>
+     for an environment with basic LaTeX support.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     It typically won't work to use separately installed packages together.
+     Instead, you can build a custom set of packages like this:
+<programlisting>
+texlive.combine {
+  inherit (texlive) scheme-small collection-langkorean algorithms cm-super;
+}
+      </programlisting>
+     There are all the schemes, collections and a few thousand packages, as
+     defined upstream (perhaps with tiny differences).
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     By default you only get executables and files needed during runtime, and a
+     little documentation for the core packages. To change that, you need to
+     add <varname>pkgFilter</varname> function to <varname>combine</varname>.
+<programlisting>
+texlive.combine {
+  # inherit (texlive) whatever-you-want;
+  pkgFilter = pkg:
+    pkg.tlType == "run" || pkg.tlType == "bin" || pkg.pname == "cm-super";
+  # elem tlType [ "run" "bin" "doc" "source" ]
+  # there are also other attributes: version, name
+}
+      </programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     You can list packages e.g. by <command>nix repl</command>.
+<programlisting><![CDATA[
+$ nix repl
+nix-repl> :l <nixpkgs>
+nix-repl> texlive.collection-<TAB>
+]]></programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Note that the wrapper assumes that the result has a chance to be useful.
+     For example, the core executables should be present, as well as some core
+     data files. The supported way of ensuring this is by including some
+     scheme, for example <varname>scheme-basic</varname>, into the combination.
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+
+ <section xml:id="sec-language-texlive-known-problems">
+  <title>Known problems</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Some tools are still missing, e.g. luajittex;
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     some apps aren't packaged/tested yet (asymptote, biber, etc.);
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     feature/bug: when a package is rejected by <varname>pkgFilter</varname>,
+     its dependencies are still propagated;
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     in case of any bugs or feature requests, file a github issue or better a
+     pull request and /cc @vcunat.
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+</section>
diff --git a/nixpkgs/doc/languages-frameworks/titanium.section.md b/nixpkgs/doc/languages-frameworks/titanium.section.md
new file mode 100644
index 000000000000..7a97664ec598
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/titanium.section.md
@@ -0,0 +1,115 @@
+---
+title: Titanium
+author: Sander van der Burg
+date: 2018-11-18
+---
+# Titanium
+
+The Nixpkgs repository contains facilities to deploy a variety of versions of
+the [Titanium SDK](https://www.appcelerator.com) versions, a cross-platform
+mobile app development framework using JavaScript as an implementation language,
+and includes a function abstraction making it possible to build Titanium
+applications for Android and iOS devices from source code.
+
+Not all Titanium features supported -- currently, it can only be used to build
+Android and iOS apps.
+
+Building a Titanium app
+-----------------------
+We can build a Titanium app from source for Android or iOS and for debugging or
+release purposes by invoking the `titaniumenv.buildApp {}` function:
+
+```nix
+titaniumenv.buildApp {
+  name = "myapp";
+  src = ./myappsource;
+
+  preBuild = "";
+  target = "android"; # or 'iphone'
+  tiVersion = "7.1.0.GA";
+  release = true;
+
+  androidsdkArgs = {
+    platformVersions = [ "25" "26" ];
+  };
+  androidKeyStore = ./keystore;
+  androidKeyAlias = "myfirstapp";
+  androidKeyStorePassword = "secret";
+
+  xcodeBaseDir = "/Applications/Xcode.app";
+  xcodewrapperArgs = {
+    version = "9.3";
+  };
+  iosMobileProvisioningProfile = ./myprovisioning.profile;
+  iosCertificateName = "My Company";
+  iosCertificate = ./mycertificate.p12;
+  iosCertificatePassword = "secret";
+  iosVersion = "11.3";
+  iosBuildStore = false;
+
+  enableWirelessDistribution = true;
+  installURL = "/installipa.php";
+}
+```
+
+The `titaniumenv.buildApp {}` function takes the following parameters:
+
+* The `name` parameter refers to the name in the Nix store.
+* The `src` parameter refers to the source code location of the app that needs
+  to be built.
+* `preRebuild` contains optional build instructions that are carried out before
+  the build starts.
+* `target` indicates for which device the app must be built. Currently only
+  'android' and 'iphone' (for iOS) are supported.
+* `tiVersion` can be used to optionally override the requested Titanium version
+  in `tiapp.xml`. If not specified, it will use the version in `tiapp.xml`.
+* `release` should be set to true when building an app for submission to the
+  Google Playstore or Apple Appstore. Otherwise, it should be false.
+
+When the `target` has been set to `android`, we can configure the following
+parameters:
+
+* The `androidSdkArgs` parameter refers to an attribute set that propagates all
+  parameters to the `androidenv.composeAndroidPackages {}` function. This can
+  be used to install all relevant Android plugins that may be needed to perform
+  the Android build. If no parameters are given, it will deploy the platform
+  SDKs for API-levels 25 and 26 by default.
+
+When the `release` parameter has been set to true, you need to provide
+parameters to sign the app:
+
+* `androidKeyStore` is the path to the keystore file
+* `androidKeyAlias` is the key alias
+* `androidKeyStorePassword` refers to the password to open the keystore file.
+
+When the `target` has been set to `iphone`, we can configure the following
+parameters:
+
+* The `xcodeBaseDir` parameter refers to the location where Xcode has been
+  installed. When none value is given, the above value is the default.
+* The `xcodewrapperArgs` parameter passes arbitrary parameters to the
+  `xcodeenv.composeXcodeWrapper {}` function. This can, for example, be used
+  to adjust the default version of Xcode.
+
+When `release` has been set to true, you also need to provide the following
+parameters:
+
+* `iosMobileProvisioningProfile` refers to a mobile provisioning profile needed
+  for signing.
+* `iosCertificateName` refers to the company name in the P12 certificate.
+* `iosCertificate` refers to the path to the P12 file.
+* `iosCertificatePassword` contains the password to open the P12 file.
+* `iosVersion` refers to the iOS SDK version to use. It defaults to the latest
+  version.
+* `iosBuildStore` should be set to `true` when building for the Apple Appstore
+  submission. For enterprise or ad-hoc builds it should be set to `false`.
+
+When `enableWirelessDistribution` has been enabled, you must also provide the
+path of the PHP script (`installURL`) (that is included with the iOS build
+environment) to enable wireless ad-hoc installations.
+
+Emulating or simulating the app
+-------------------------------
+It is also possible to simulate the correspond iOS simulator build by using
+`xcodeenv.simulateApp {}` and emulate an Android APK by using
+`androidenv.emulateApp {}`.
diff --git a/nixpkgs/doc/languages-frameworks/vim.section.md b/nixpkgs/doc/languages-frameworks/vim.section.md
new file mode 100644
index 000000000000..6ed60028ae20
--- /dev/null
+++ b/nixpkgs/doc/languages-frameworks/vim.section.md
@@ -0,0 +1,240 @@
+---
+title: User's Guide for Vim in Nixpkgs
+author: Marc Weber
+date: 2016-06-25
+---
+# User's Guide to Vim Plugins/Addons/Bundles/Scripts in Nixpkgs
+
+Both Neovim and Vim can be configured to include your favorite plugins
+and additional libraries.
+
+Loading can be deferred; see examples.
+
+At the moment we support three different methods for managing plugins:
+
+- Vim packages (*recommend*)
+- VAM (=vim-addon-manager)
+- Pathogen
+- vim-plug
+
+## Custom configuration
+
+Adding custom .vimrc lines can be done using the following code:
+
+```
+vim_configurable.customize {
+  # `name` specifies the name of the executable and package
+  name = "vim-with-plugins";
+
+  vimrcConfig.customRC = ''
+    set hidden
+  '';
+}
+```
+
+This configuration is used when vim is invoked with the command specified as name, in this case `vim-with-plugins`.
+
+For Neovim the `configure` argument can be overridden to achieve the same:
+
+```
+neovim.override {
+  configure = {
+    customRC = ''
+      # here your custom configuration goes!
+    '';
+  };
+}
+```
+
+## Managing plugins with Vim packages
+
+To store you plugins in Vim packages (the native vim plugin manager, see `:help packages`) the following example can be used:
+
+```
+vim_configurable.customize {
+  vimrcConfig.packages.myVimPackage = with pkgs.vimPlugins; {
+    # loaded on launch
+    start = [ youcompleteme fugitive ];
+    # manually loadable by calling `:packadd $plugin-name`
+    # however, if a vim plugin has a dependency that is not explicitly listed in
+	# opt that dependency will always be added to start to avoid confusion.
+    opt = [ phpCompletion elm-vim ];
+    # To automatically load a plugin when opening a filetype, add vimrc lines like:
+    # autocmd FileType php :packadd phpCompletion
+  };
+}
+```
+
+`myVimPackage` is an arbitrary name for the generated package. You can choose any name you like.
+For Neovim the syntax is:
+
+```
+neovim.override {
+  configure = {
+    customRC = ''
+      # here your custom configuration goes!
+    '';
+    packages.myVimPackage = with pkgs.vimPlugins; {
+      # see examples below how to use custom packages
+      start = [ ];
+      # If a vim plugin has a dependency that is not explicitly listed in
+      # opt that dependency will always be added to start to avoid confusion.
+      opt = [ ];
+    };
+  };
+}
+```
+
+The resulting package can be added to `packageOverrides` in `~/.nixpkgs/config.nix` to make it installable:
+
+```
+{
+  packageOverrides = pkgs: with pkgs; {
+    myVim = vim_configurable.customize {
+      # `name` specifies the name of the executable and package
+      name = "vim-with-plugins";
+      # add here code from the example section
+    };
+    myNeovim = neovim.override {
+      configure = {
+      # add here code from the example section
+      };
+    };
+  };
+}
+```
+
+After that you can install your special grafted `myVim` or `myNeovim` packages.
+
+## Managing plugins with vim-plug
+
+To use [vim-plug](https://github.com/junegunn/vim-plug) to manage your Vim
+plugins the following example can be used:
+
+```
+vim_configurable.customize {
+  vimrcConfig.packages.myVimPackage = with pkgs.vimPlugins; {
+    # loaded on launch
+    plug.plugins = [ youcompleteme fugitive phpCompletion elm-vim ];
+  };
+}
+```
+
+For Neovim the syntax is:
+
+```
+neovim.override {
+  configure = {
+    customRC = ''
+      # here your custom configuration goes!
+    '';
+    plug.plugins = with pkgs.vimPlugins; [
+      vim-go
+    ];
+  };
+}
+```
+
+## Managing plugins with VAM
+
+### Handling dependencies of Vim plugins
+
+VAM introduced .json files supporting dependencies without versioning
+assuming that "using latest version" is ok most of the time.
+
+### Example
+
+First create a vim-scripts file having one plugin name per line. Example:
+
+    "tlib"
+    {'name': 'vim-addon-sql'}
+    {'filetype_regex': '\%(vim)$', 'names': ['reload', 'vim-dev-plugin']}
+
+Such vim-scripts file can be read by VAM as well like this:
+
+    call vam#Scripts(expand('~/.vim-scripts'), {})
+
+Create a default.nix file:
+
+    { nixpkgs ? import <nixpkgs> {}, compiler ? "ghc7102" }:
+    nixpkgs.vim_configurable.customize { name = "vim"; vimrcConfig.vam.pluginDictionaries = [ "vim-addon-vim2nix" ]; }
+
+Create a generate.vim file:
+
+    ActivateAddons vim-addon-vim2nix
+    let vim_scripts = "vim-scripts"
+    call nix#ExportPluginsForNix({
+    \  'path_to_nixpkgs': eval('{"'.substitute(substitute(substitute($NIX_PATH, ':', ',', 'g'), '=',':', 'g'), '\([:,]\)', '"\1"',"g").'"}')["nixpkgs"],
+    \  'cache_file': '/tmp/vim2nix-cache',
+    \  'try_catch': 0,
+    \  'plugin_dictionaries': ["vim-addon-manager"]+map(readfile(vim_scripts), 'eval(v:val)')
+    \ })
+
+Then run
+
+    nix-shell -p vimUtils.vim_with_vim2nix --command "vim -c 'source generate.vim'"
+
+You should get a Vim buffer with the nix derivations (output1) and vam.pluginDictionaries (output2).
+You can add your vim to your system's configuration file like this and start it by "vim-my":
+
+    my-vim =
+     let plugins = let inherit (vimUtils) buildVimPluginFrom2Nix; in {
+          copy paste output1 here
+     }; in vim_configurable.customize {
+       name = "vim-my";
+
+       vimrcConfig.vam.knownPlugins = plugins; # optional
+       vimrcConfig.vam.pluginDictionaries = [
+          copy paste output2 here
+       ];
+
+       # Pathogen would be
+       # vimrcConfig.pathogen.knownPlugins = plugins; # plugins
+       # vimrcConfig.pathogen.pluginNames = ["tlib"];
+     };
+
+
+Sample output1:
+
+    "reload" = buildVimPluginFrom2Nix { # created by nix#NixDerivation
+      name = "reload";
+      src = fetchgit {
+        url = "git://github.com/xolox/vim-reload";
+        rev = "0a601a668727f5b675cb1ddc19f6861f3f7ab9e1";
+        sha256 = "0vb832l9yxj919f5hfg6qj6bn9ni57gnjd3bj7zpq7d4iv2s4wdh";
+      };
+      dependencies = ["nim-misc"];
+
+    };
+    [...]
+
+Sample output2:
+
+    [
+      ''vim-addon-manager''
+      ''tlib''
+      { "name" = ''vim-addon-sql''; }
+      { "filetype_regex" = ''\%(vim)$$''; "names" = [ ''reload'' ''vim-dev-plugin'' ]; }
+    ]
+
+
+## Adding new plugins to nixpkgs
+
+In `pkgs/misc/vim-plugins/vim-plugin-names` we store the plugin names
+for all vim plugins we automatically generate plugins for.
+The format of this file `github username/github repository`:
+For example https://github.com/scrooloose/nerdtree becomes `scrooloose/nerdtree`.
+After adding your plugin to this file run the `./update.py` in the same folder.
+This will updated a file called `generated.nix` and make your plugin accessible in the
+`vimPlugins` attribute set (`vimPlugins.nerdtree` in our example).
+If additional steps to the build process of the plugin are required, add an
+override to the `pkgs/misc/vim-plugins/default.nix` in the same directory.
+
+## Important repositories
+
+- [vim-pi](https://bitbucket.org/vimcommunity/vim-pi) is a plugin repository
+  from VAM plugin manager meant to be used by others as well used by
+
+- [vim2nix](http://github.com/MarcWeber/vim-addon-vim2nix) which generates the
+  .nix code
+
diff --git a/nixpkgs/doc/lib-function-locations.nix b/nixpkgs/doc/lib-function-locations.nix
new file mode 100644
index 000000000000..ae7036e46264
--- /dev/null
+++ b/nixpkgs/doc/lib-function-locations.nix
@@ -0,0 +1,85 @@
+{ pkgs ? (import ./.. { }), nixpkgs ? { }}:
+let
+  revision = pkgs.lib.trivial.revisionWithDefault (nixpkgs.revision or "master");
+
+  libDefPos = set:
+    builtins.map
+      (name: {
+        name = name;
+        location = builtins.unsafeGetAttrPos name set;
+      })
+      (builtins.attrNames set);
+
+  libset = toplib:
+    builtins.map
+      (subsetname: {
+        subsetname = subsetname;
+        functions = libDefPos toplib."${subsetname}";
+      })
+      (builtins.filter
+        (name: builtins.isAttrs toplib."${name}")
+        (builtins.attrNames toplib));
+
+  nixpkgsLib = pkgs.lib;
+
+  flattenedLibSubset = { subsetname, functions }:
+  builtins.map
+    (fn: {
+      name = "lib.${subsetname}.${fn.name}";
+      value = fn.location;
+    })
+    functions;
+
+  locatedlibsets = libs: builtins.map flattenedLibSubset (libset libs);
+  removeFilenamePrefix = prefix: filename:
+    let
+    prefixLen = (builtins.stringLength prefix) + 1; # +1 to remove the leading /
+      filenameLen = builtins.stringLength filename;
+      substr = builtins.substring prefixLen filenameLen filename;
+      in substr;
+
+  removeNixpkgs = removeFilenamePrefix (builtins.toString pkgs.path);
+
+  liblocations =
+    builtins.filter
+      (elem: elem.value != null)
+      (nixpkgsLib.lists.flatten
+        (locatedlibsets nixpkgsLib));
+
+  fnLocationRelative = { name, value }:
+    {
+      inherit name;
+      value = value // { file = removeNixpkgs value.file; };
+    };
+
+  relativeLocs = (builtins.map fnLocationRelative liblocations);
+  sanitizeId = builtins.replaceStrings
+    [ "'"      ]
+    [ "-prime" ];
+
+  urlPrefix = "https://github.com/NixOS/nixpkgs/blob/${revision}";
+  xmlstrings = (nixpkgsLib.strings.concatMapStrings
+      ({ name, value }:
+      ''
+      <section><title>${name}</title>
+        <para xml:id="${sanitizeId name}">
+        Located at
+        <link
+          xlink:href="${urlPrefix}/${value.file}#L${builtins.toString value.line}">${value.file}:${builtins.toString value.line}</link>
+        in  <literal>&lt;nixpkgs&gt;</literal>.
+        </para>
+        </section>
+      '')
+      relativeLocs);
+
+in pkgs.writeText
+    "locations.xml"
+    ''
+    <section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         version="5">
+         <title>All the locations for every lib function</title>
+         <para>This file is only for inclusion by other files.</para>
+         ${xmlstrings}
+    </section>
+    ''
diff --git a/nixpkgs/doc/manual.xml b/nixpkgs/doc/manual.xml
new file mode 100644
index 000000000000..f31897aed039
--- /dev/null
+++ b/nixpkgs/doc/manual.xml
@@ -0,0 +1,24 @@
+<book xmlns="http://docbook.org/ns/docbook"
+      xmlns:xi="http://www.w3.org/2001/XInclude">
+ <info>
+  <title>Nixpkgs Contributors Guide</title>
+  <subtitle>Version <xi:include href=".version" parse="text" />
+  </subtitle>
+ </info>
+ <xi:include href="introduction.chapter.xml" />
+ <xi:include href="quick-start.xml" />
+ <xi:include href="stdenv.xml" />
+ <xi:include href="multiple-output.xml" />
+ <xi:include href="cross-compilation.xml" />
+ <xi:include href="configuration.xml" />
+ <xi:include href="functions.xml" />
+ <xi:include href="meta.xml" />
+ <xi:include href="languages-frameworks/index.xml" />
+ <xi:include href="platform-notes.xml" />
+ <xi:include href="package-notes.xml" />
+ <xi:include href="overlays.xml" />
+ <xi:include href="coding-conventions.xml" />
+ <xi:include href="submitting-changes.xml" />
+ <xi:include href="reviewing-contributions.xml" />
+ <xi:include href="contributing.xml" />
+</book>
diff --git a/nixpkgs/doc/meta.xml b/nixpkgs/doc/meta.xml
new file mode 100644
index 000000000000..774ed2db7500
--- /dev/null
+++ b/nixpkgs/doc/meta.xml
@@ -0,0 +1,431 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-meta">
+ <title>Meta-attributes</title>
+ <para>
+  Nix packages can declare <emphasis>meta-attributes</emphasis> that contain
+  information about a package such as a description, its homepage, its license,
+  and so on. For instance, the GNU Hello package has a <varname>meta</varname>
+  declaration like this:
+<programlisting>
+meta = with stdenv.lib; {
+  description = "A program that produces a familiar, friendly greeting";
+  longDescription = ''
+    GNU Hello is a program that prints "Hello, world!" when you run it.
+    It is fully customizable.
+  '';
+  homepage = https://www.gnu.org/software/hello/manual/;
+  license = licenses.gpl3Plus;
+  maintainers = [ maintainers.eelco ];
+  platforms = platforms.all;
+};
+</programlisting>
+ </para>
+ <para>
+  Meta-attributes are not passed to the builder of the package. Thus, a change
+  to a meta-attribute doesn’t trigger a recompilation of the package. The
+  value of a meta-attribute must be a string.
+ </para>
+ <para>
+  The meta-attributes of a package can be queried from the command-line using
+  <command>nix-env</command>:
+<screen>
+$ nix-env -qa hello --json
+{
+    "hello": {
+        "meta": {
+            "description": "A program that produces a familiar, friendly greeting",
+            "homepage": "https://www.gnu.org/software/hello/manual/",
+            "license": {
+                "fullName": "GNU General Public License version 3 or later",
+                "shortName": "GPLv3+",
+                "url": "http://www.fsf.org/licensing/licenses/gpl.html"
+            },
+            "longDescription": "GNU Hello is a program that prints \"Hello, world!\" when you run it.\nIt is fully customizable.\n",
+            "maintainers": [
+                "Ludovic Court\u00e8s &lt;ludo@gnu.org>"
+            ],
+            "platforms": [
+                "i686-linux",
+                "x86_64-linux",
+                "armv5tel-linux",
+                "armv7l-linux",
+                "mips32-linux",
+                "x86_64-darwin",
+                "i686-cygwin",
+                "i686-freebsd",
+                "x86_64-freebsd",
+                "i686-openbsd",
+                "x86_64-openbsd"
+            ],
+            "position": "/home/user/dev/nixpkgs/pkgs/applications/misc/hello/default.nix:14"
+        },
+        "name": "hello-2.9",
+        "system": "x86_64-linux"
+    }
+}
+
+
+</screen>
+  <command>nix-env</command> knows about the <varname>description</varname>
+  field specifically:
+<screen>
+$ nix-env -qa hello --description
+hello-2.3  A program that produces a familiar, friendly greeting
+</screen>
+ </para>
+ <section xml:id="sec-standard-meta-attributes">
+  <title>Standard meta-attributes</title>
+
+  <para>
+   It is expected that each meta-attribute is one of the following:
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>description</varname>
+    </term>
+    <listitem>
+     <para>
+      A short (one-line) description of the package. This is shown by
+      <command>nix-env -q --description</command> and also on the Nixpkgs
+      release pages.
+     </para>
+     <para>
+      Don’t include a period at the end. Don’t include newline characters.
+      Capitalise the first character. For brevity, don’t repeat the name of
+      package — just describe what it does.
+     </para>
+     <para>
+      Wrong: <literal>"libpng is a library that allows you to decode PNG
+      images."</literal>
+     </para>
+     <para>
+      Right: <literal>"A library for decoding PNG images"</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>longDescription</varname>
+    </term>
+    <listitem>
+     <para>
+      An arbitrarily long description of the package.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>branch</varname>
+    </term>
+    <listitem>
+     <para>
+      Release branch. Used to specify that a package is not going to receive
+      updates that are not in this branch; for example, Linux kernel 3.0 is
+      supposed to be updated to 3.0.X, not 3.1.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>homepage</varname>
+    </term>
+    <listitem>
+     <para>
+      The package’s homepage. Example:
+      <literal>https://www.gnu.org/software/hello/manual/</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>downloadPage</varname>
+    </term>
+    <listitem>
+     <para>
+      The page where a link to the current version can be found. Example:
+      <literal>https://ftp.gnu.org/gnu/hello/</literal>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>license</varname>
+    </term>
+    <listitem>
+     <para>
+      The license, or licenses, for the package. One from the attribute set
+      defined in
+      <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/licenses.nix">
+      <filename>nixpkgs/lib/licenses.nix</filename></link>. At this moment
+      using both a list of licenses and a single license is valid. If the
+      license field is in the form of a list representation, then it means that
+      parts of the package are licensed differently. Each license should
+      preferably be referenced by their attribute. The non-list attribute value
+      can also be a space delimited string representation of the contained
+      attribute shortNames or spdxIds. The following are all valid examples:
+      <itemizedlist>
+       <listitem>
+        <para>
+         Single license referenced by attribute (preferred)
+         <literal>stdenv.lib.licenses.gpl3</literal>.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Single license referenced by its attribute shortName (frowned upon)
+         <literal>"gpl3"</literal>.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Single license referenced by its attribute spdxId (frowned upon)
+         <literal>"GPL-3.0"</literal>.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Multiple licenses referenced by attribute (preferred) <literal>with
+         stdenv.lib.licenses; [ asl20 free ofl ]</literal>.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Multiple licenses referenced as a space delimited string of attribute
+         shortNames (frowned upon) <literal>"asl20 free ofl"</literal>.
+        </para>
+       </listitem>
+      </itemizedlist>
+      For details, see <xref linkend='sec-meta-license'/>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>maintainers</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of names and e-mail addresses of the maintainers of this Nix
+      expression. If you would like to be a maintainer of a package, you may
+      want to add yourself to
+      <link
+    xlink:href="https://github.com/NixOS/nixpkgs/blob/master/maintainers/maintainer-list.nix"><filename>nixpkgs/maintainers/maintainer-list.nix</filename></link>
+      and write something like <literal>[ stdenv.lib.maintainers.alice
+      stdenv.lib.maintainers.bob ]</literal>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>priority</varname>
+    </term>
+    <listitem>
+     <para>
+      The <emphasis>priority</emphasis> of the package, used by
+      <command>nix-env</command> to resolve file name conflicts between
+      packages. See the Nix manual page for <command>nix-env</command> for
+      details. Example: <literal>"10"</literal> (a low-priority package).
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>platforms</varname>
+    </term>
+    <listitem>
+     <para>
+      The list of Nix platform types on which the package is supported. Hydra
+      builds packages according to the platform specified. If no platform is
+      specified, the package does not have prebuilt binaries. An example is:
+<programlisting>
+meta.platforms = stdenv.lib.platforms.linux;
+</programlisting>
+      Attribute Set <varname>stdenv.lib.platforms</varname> defines
+      <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/systems/doubles.nix">
+      various common lists</link> of platforms types.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>tests</varname>
+    </term>
+    <listitem>
+     <warning>
+      <para>
+       This attribute is special in that it is not actually under the
+       <literal>meta</literal> attribute set but rather under the
+       <literal>passthru</literal> attribute set. This is due to a current
+       limitation of Nix, and will change as soon as Nixpkgs will be able to
+       depend on a new enough version of Nix. See
+       <link xlink:href="https://github.com/NixOS/nix/issues/2532">the relevant
+       issue</link> for more details.
+      </para>
+     </warning>
+     <para>
+      An attribute set with as values tests. A test is a derivation, which
+      builds successfully when the test passes, and fails to build otherwise. A
+      derivation that is a test needs to have <literal>meta.timeout</literal>
+      defined.
+     </para>
+     <para>
+      The NixOS tests are available as <literal>nixosTests</literal> in
+      parameters of derivations. For instance, the OpenSMTPD derivation
+      includes lines similar to:
+<programlisting>
+{ /* ... */, nixosTests }:
+{
+  # ...
+  passthru.tests = {
+    basic-functionality-and-dovecot-integration = nixosTests.opensmtpd;
+  };
+}
+</programlisting>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>timeout</varname>
+    </term>
+    <listitem>
+     <para>
+      A timeout (in seconds) for building the derivation. If the derivation
+      takes longer than this time to build, it can fail due to breaking the
+      timeout. However, all computers do not have the same computing power,
+      hence some builders may decide to apply a multiplicative factor to this
+      value. When filling this value in, try to keep it approximately
+      consistent with other values already present in
+      <literal>nixpkgs</literal>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>hydraPlatforms</varname>
+    </term>
+    <listitem>
+     <para>
+      The list of Nix platform types for which the Hydra instance at
+      <literal>hydra.nixos.org</literal> will build the package. (Hydra is the
+      Nix-based continuous build system.) It defaults to the value of
+      <varname>meta.platforms</varname>. Thus, the only reason to set
+      <varname>meta.hydraPlatforms</varname> is if you want
+      <literal>hydra.nixos.org</literal> to build the package on a subset of
+      <varname>meta.platforms</varname>, or not at all, e.g.
+<programlisting>
+meta.platforms = stdenv.lib.platforms.linux;
+meta.hydraPlatforms = [];
+</programlisting>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>broken</varname>
+    </term>
+    <listitem>
+     <para>
+      If set to <literal>true</literal>, the package is marked as “broken”,
+      meaning that it won’t show up in <literal>nix-env -qa</literal>, and
+      cannot be built or installed. Such packages should be removed from
+      Nixpkgs eventually unless they are fixed.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>updateWalker</varname>
+    </term>
+    <listitem>
+     <para>
+      If set to <literal>true</literal>, the package is tested to be updated
+      correctly by the <literal>update-walker.sh</literal> script without
+      additional settings. Such packages have <varname>meta.version</varname>
+      set and their homepage (or the page specified by
+      <varname>meta.downloadPage</varname>) contains a direct link to the
+      package tarball.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+ </section>
+ <section xml:id="sec-meta-license">
+  <title>Licenses</title>
+
+  <para>
+   The <varname>meta.license</varname> attribute should preferrably contain a
+   value from <varname>stdenv.lib.licenses</varname> defined in
+   <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/lib/licenses.nix">
+   <filename>nixpkgs/lib/licenses.nix</filename></link>, or in-place license
+   description of the same format if the license is unlikely to be useful in
+   another expression.
+  </para>
+
+  <para>
+   Although it's typically better to indicate the specific license, a few
+   generic options are available:
+   <variablelist>
+    <varlistentry>
+     <term>
+      <varname>stdenv.lib.licenses.free</varname>, <varname>"free"</varname>
+     </term>
+     <listitem>
+      <para>
+       Catch-all for free software licenses not listed above.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>stdenv.lib.licenses.unfreeRedistributable</varname>, <varname>"unfree-redistributable"</varname>
+     </term>
+     <listitem>
+      <para>
+       Unfree package that can be redistributed in binary form. That is, it’s
+       legal to redistribute the <emphasis>output</emphasis> of the derivation.
+       This means that the package can be included in the Nixpkgs channel.
+      </para>
+      <para>
+       Sometimes proprietary software can only be redistributed unmodified.
+       Make sure the builder doesn’t actually modify the original binaries;
+       otherwise we’re breaking the license. For instance, the NVIDIA X11
+       drivers can be redistributed unmodified, but our builder applies
+       <command>patchelf</command> to make them work. Thus, its license is
+       <varname>"unfree"</varname> and it cannot be included in the Nixpkgs
+       channel.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>stdenv.lib.licenses.unfree</varname>, <varname>"unfree"</varname>
+     </term>
+     <listitem>
+      <para>
+       Unfree package that cannot be redistributed. You can build it yourself,
+       but you cannot redistribute the output of the derivation. Thus it cannot
+       be included in the Nixpkgs channel.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>stdenv.lib.licenses.unfreeRedistributableFirmware</varname>, <varname>"unfree-redistributable-firmware"</varname>
+     </term>
+     <listitem>
+      <para>
+       This package supplies unfree, redistributable firmware. This is a
+       separate value from <varname>unfree-redistributable</varname> because
+       not everybody cares whether firmware is free.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </para>
+ </section>
+</chapter>
diff --git a/nixpkgs/doc/multiple-output.xml b/nixpkgs/doc/multiple-output.xml
new file mode 100644
index 000000000000..d18e282c5bd3
--- /dev/null
+++ b/nixpkgs/doc/multiple-output.xml
@@ -0,0 +1,323 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE chapter [
+  <!ENTITY ndash "&#x2013;"> <!-- @vcunat likes to use this one ;-) -->
+]>
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-multiple-output">
+ <title>Multiple-output packages</title>
+ <section xml:id="sec-multiple-outputs-introduction">
+  <title>Introduction</title>
+
+  <para>
+   The Nix language allows a derivation to produce multiple outputs, which is
+   similar to what is utilized by other Linux distribution packaging systems.
+   The outputs reside in separate Nix store paths, so they can be mostly
+   handled independently of each other, including passing to build inputs,
+   garbage collection or binary substitution. The exception is that building
+   from source always produces all the outputs.
+  </para>
+
+  <para>
+   The main motivation is to save disk space by reducing runtime closure sizes;
+   consequently also sizes of substituted binaries get reduced. Splitting can
+   be used to have more granular runtime dependencies, for example the typical
+   reduction is to split away development-only files, as those are typically
+   not needed during runtime. As a result, closure sizes of many packages can
+   get reduced to a half or even much less.
+  </para>
+
+  <note>
+   <para>
+    The reduction effects could be instead achieved by building the parts in
+    completely separate derivations. That would often additionally reduce
+    build-time closures, but it tends to be much harder to write such
+    derivations, as build systems typically assume all parts are being built at
+    once. This compromise approach of single source package producing multiple
+    binary packages is also utilized often by rpm and deb.
+   </para>
+  </note>
+ </section>
+ <section xml:id="sec-multiple-outputs-installing">
+  <title>Installing a split package</title>
+
+  <para>
+   When installing a package via <varname>systemPackages</varname> or
+   <command>nix-env</command> you have several options:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     You can install particular outputs explicitly, as each is available in the
+     Nix language as an attribute of the package. The
+     <varname>outputs</varname> attribute contains a list of output names.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     You can let it use the default outputs. These are handled by
+     <varname>meta.outputsToInstall</varname> attribute that contains a list of
+     output names.
+    </para>
+    <para>
+     TODO: more about tweaking the attribute, etc.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     NixOS provides configuration option
+     <varname>environment.extraOutputsToInstall</varname> that allows adding
+     extra outputs of <varname>environment.systemPackages</varname> atop the
+     default ones. It's mainly meant for documentation and debug symbols, and
+     it's also modified by specific options.
+    </para>
+    <note>
+     <para>
+      At this moment there is no similar configurability for packages installed
+      by <command>nix-env</command>. You can still use approach from
+      <xref linkend="sec-modify-via-packageOverrides" /> to override
+      <varname>meta.outputsToInstall</varname> attributes, but that's a rather
+      inconvenient way.
+     </para>
+    </note>
+   </listitem>
+  </itemizedlist>
+ </section>
+ <section xml:id="sec-multiple-outputs-using-split-packages">
+  <title>Using a split package</title>
+
+  <para>
+   In the Nix language the individual outputs can be reached explicitly as
+   attributes, e.g. <varname>coreutils.info</varname>, but the typical case is
+   just using packages as build inputs.
+  </para>
+
+  <para>
+   When a multiple-output derivation gets into a build input of another
+   derivation, the <varname>dev</varname> output is added if it exists,
+   otherwise the first output is added. In addition to that,
+   <varname>propagatedBuildOutputs</varname> of that package which by default
+   contain <varname>$outputBin</varname> and <varname>$outputLib</varname> are
+   also added. (See <xref linkend="multiple-output-file-type-groups" />.)
+  </para>
+ </section>
+ <section xml:id="sec-multiple-outputs-">
+  <title>Writing a split derivation</title>
+
+  <para>
+   Here you find how to write a derivation that produces multiple outputs.
+  </para>
+
+  <para>
+   In nixpkgs there is a framework supporting multiple-output derivations. It
+   tries to cover most cases by default behavior. You can find the source
+   separated in
+   &lt;<filename>nixpkgs/pkgs/build-support/setup-hooks/multiple-outputs.sh</filename>&gt;;
+   it's relatively well-readable. The whole machinery is triggered by defining
+   the <varname>outputs</varname> attribute to contain the list of desired
+   output names (strings).
+  </para>
+
+<programlisting>outputs = [ "bin" "dev" "out" "doc" ];</programlisting>
+
+  <para>
+   Often such a single line is enough. For each output an equally named
+   environment variable is passed to the builder and contains the path in nix
+   store for that output. Typically you also want to have the main
+   <varname>out</varname> output, as it catches any files that didn't get
+   elsewhere.
+  </para>
+
+  <note>
+   <para>
+    There is a special handling of the <varname>debug</varname> output,
+    described at <xref linkend="stdenv-separateDebugInfo" />.
+   </para>
+  </note>
+
+  <section xml:id="multiple-output-file-binaries-first-convention">
+   <title><quote>Binaries first</quote></title>
+
+   <para>
+    A commonly adopted convention in <literal>nixpkgs</literal> is that
+    executables provided by the package are contained within its first output.
+    This convention allows the dependent packages to reference the executables
+    provided by packages in a uniform manner. For instance, provided with the
+    knowledge that the <literal>perl</literal> package contains a
+    <literal>perl</literal> executable it can be referenced as
+    <literal>${pkgs.perl}/bin/perl</literal> within a Nix derivation that needs
+    to execute a Perl script.
+   </para>
+
+   <para>
+    The <literal>glibc</literal> package is a deliberate single exception to
+    the <quote>binaries first</quote> convention. The <literal>glibc</literal>
+    has <literal>libs</literal> as its first output allowing the libraries
+    provided by <literal>glibc</literal> to be referenced directly (e.g.
+    <literal>${stdenv.glibc}/lib/ld-linux-x86-64.so.2</literal>). The
+    executables provided by <literal>glibc</literal> can be accessed via its
+    <literal>bin</literal> attribute (e.g.
+    <literal>${stdenv.glibc.bin}/bin/ldd</literal>).
+   </para>
+
+   <para>
+    The reason for why <literal>glibc</literal> deviates from the convention is
+    because referencing a library provided by <literal>glibc</literal> is a
+    very common operation among Nix packages. For instance, third-party
+    executables packaged by Nix are typically patched and relinked with the
+    relevant version of <literal>glibc</literal> libraries from Nix packages
+    (please see the documentation on
+    <link xlink:href="https://nixos.org/patchelf.html">patchelf</link> for more
+    details).
+   </para>
+  </section>
+
+  <section xml:id="multiple-output-file-type-groups">
+   <title>File type groups</title>
+
+   <para>
+    The support code currently recognizes some particular kinds of outputs and
+    either instructs the build system of the package to put files into their
+    desired outputs or it moves the files during the fixup phase. Each group of
+    file types has an <varname>outputFoo</varname> variable specifying the
+    output name where they should go. If that variable isn't defined by the
+    derivation writer, it is guessed &ndash; a default output name is defined,
+    falling back to other possibilities if the output isn't defined.
+   </para>
+
+   <variablelist>
+    <varlistentry>
+     <term>
+      <varname> $outputDev</varname>
+     </term>
+     <listitem>
+      <para>
+       is for development-only files. These include C(++) headers, pkg-config,
+       cmake and aclocal files. They go to <varname>dev</varname> or
+       <varname>out</varname> by default.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname> $outputBin</varname>
+     </term>
+     <listitem>
+      <para>
+       is meant for user-facing binaries, typically residing in bin/. They go
+       to <varname>bin</varname> or <varname>out</varname> by default.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname> $outputLib</varname>
+     </term>
+     <listitem>
+      <para>
+       is meant for libraries, typically residing in <filename>lib/</filename>
+       and <filename>libexec/</filename>. They go to <varname>lib</varname> or
+       <varname>out</varname> by default.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname> $outputDoc</varname>
+     </term>
+     <listitem>
+      <para>
+       is for user documentation, typically residing in
+       <filename>share/doc/</filename>. It goes to <varname>doc</varname> or
+       <varname>out</varname> by default.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname> $outputDevdoc</varname>
+     </term>
+     <listitem>
+      <para>
+       is for <emphasis>developer</emphasis> documentation. Currently we count
+       gtk-doc and devhelp books in there. It goes to <varname>devdoc</varname>
+       or is removed (!) by default. This is because e.g. gtk-doc tends to be
+       rather large and completely unused by nixpkgs users.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname> $outputMan</varname>
+     </term>
+     <listitem>
+      <para>
+       is for man pages (except for section 3). They go to
+       <varname>man</varname> or <varname>$outputBin</varname> by default.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname> $outputDevman</varname>
+     </term>
+     <listitem>
+      <para>
+       is for section 3 man pages. They go to <varname>devman</varname> or
+       <varname>$outputMan</varname> by default.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname> $outputInfo</varname>
+     </term>
+     <listitem>
+      <para>
+       is for info pages. They go to <varname>info</varname> or
+       <varname>$outputBin</varname> by default.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="sec-multiple-outputs-caveats">
+   <title>Common caveats</title>
+
+   <itemizedlist>
+    <listitem>
+     <para>
+      Some configure scripts don't like some of the parameters passed by
+      default by the framework, e.g. <literal>--docdir=/foo/bar</literal>. You
+      can disable this by setting <literal>setOutputFlags = false;</literal>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The outputs of a single derivation can retain references to each other,
+      but note that circular references are not allowed. (And each
+      strongly-connected component would act as a single output anyway.)
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Most of split packages contain their core functionality in libraries.
+      These libraries tend to refer to various kind of data that typically gets
+      into <varname>out</varname>, e.g. locale strings, so there is often no
+      advantage in separating the libraries into <varname>lib</varname>, as
+      keeping them in <varname>out</varname> is easier.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Some packages have hidden assumptions on install paths, which complicates
+      splitting.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </section>
+ </section>
+<!--Writing a split derivation-->
+</chapter>
diff --git a/nixpkgs/doc/old/cross.txt b/nixpkgs/doc/old/cross.txt
new file mode 100644
index 000000000000..ff9fefb04a86
--- /dev/null
+++ b/nixpkgs/doc/old/cross.txt
@@ -0,0 +1,329 @@
+Setting up a cross compiler with Nix
+
+"Cross compilation" means compiling a program on one machine for another
+type of machine. A typical use of cross compilation is to compile programs
+for embedded devices. These devices often don't have the computing power
+and memory to compile programs natively.
+
+For a fully working cross compiler the following are needed:
+
+* cross binutils: assembler, archiver, linker, etcetera that understand
+the format of the target system
+
+* cross compiler: a compiler that can generate binary code and object files
+for the target platform
+
+* cross C library: a library to link object files with to create fully
+functional programs
+
+Cross compilers are difficult to set up. A lot of people report that they
+cannot succeed in building a cross toolchain successfully. The answers
+usually consist of "download this pre-built toolchain", which is equally
+unhelpful.
+
+A toolchain is set up in five steps:
+
+1. build binutils to that can run on the host platform, but generate code
+for the target platform
+
+2. build Linux kernel headers for the target platform
+
+3. build a minimal C only version of GCC, that can run on the host platform
+and generate code for the target platform
+
+4. build a C library for the target platform. This includes the dynamic
+linker, C library, etc.
+
+5. build a full GCC
+
+****
+NB:
+
+Keep in mind that many programs are not very well suited for cross
+compilation. Either they are not intended to run on other platforms,
+because the code is highly platform specific, or the configuration process
+is not written with cross compilation in mind.
+
+Nix will not solve these problems for you!
+***
+
+This document describes to set up a cross compiler to generate code for
+arm-linux with uClibc and runs on i686-linux. The "stdenv" used is the
+default from the standard Nix packages collection.
+
+Step 1: build binutils for arm-linux in the stdenv for i686-linux
+
+---
+{stdenv, fetchurl, noSysDirs}:
+
+stdenv.mkDerivation {
+  name = "binutils-2.16.1-arm";
+  builder = ./builder.sh;
+  src = fetchurl {
+    url = http://ftp.nluug.nl/gnu/binutils/binutils-2.16.1.tar.bz2;
+    sha256 = "1ian3kwh2vg6hr3ymrv48s04gijs539vzrq62xr76bxbhbwnz2np";
+  };
+  inherit noSysDirs;
+  configureFlags = [ "--target=arm-linux" ];
+}
+---
+
+This will compile binutils that will run on i686-linux, but knows the
+format used by arm-linux.
+
+Step 2: build kernel headers for the target architecture
+
+  default.nix for kernel-headers-arm:
+
+---
+{stdenv, fetchurl}:
+
+assert stdenv.buildPlatform.system == "i686-linux";
+
+stdenv.mkDerivation {
+  name = "linux-headers-2.6.13.1-arm";
+  builder = ./builder.sh;
+  src = fetchurl {
+    url = http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.13.1.tar.bz2;
+    sha256 = "12qxmc827fjhaz53kjy7vyrzsaqcg78amiqsb3qm20z26w705lma";
+  };
+}
+---
+
+  builder.sh for kernel-headers-arm:
+
+---
+source $stdenv/setup
+
+
+buildPhase() {
+    make include/linux/version.h
+}
+
+buildPhase=buildPhase
+
+
+installPhase() {
+    mkdir $out
+    mkdir $out/include
+    #cd $out/include
+    #ln -s asm-arm asm
+    make include/asm ARCH=arm
+    cp -prvd include/linux include/asm include/asm-arm include/asm-generic $out/include
+    echo -n > $out/include/linux/autoconf.h
+}
+
+installPhase=installPhase
+
+
+genericBuild
+---
+
+Step 3: build a minimal GCC
+
+Extra/different parameters include the target platform and the kernel
+headers argument (this needs a major cleanup, as well as the name, it
+needs to be different!). Profiled compilers are disabled. The tarball
+used here is just gcc-core. For some reason it doesn't install nicely
+if the whole tarball is used (or is this some braino on my side? -- AH).
+
+Only C is used, because for other languages (such as C++) extra libraries
+need to be compiled, for which libraries compiled for the target system
+are needed.
+
+There is a bit of evilness going on. The cross compiled utilities need
+to be either copied to or be linked from the output tree of the compiler.
+(Is this really true? Back this up with arguments! -- AH)
+
+Symbolic links are not something we want inside the Nix store.
+
+---
+{ stdenv, fetchurl, noSysDirs
+, langC ? true, langCC ? true, langF77 ? false
+, profiledCompiler ? false
+, binutilsArm
+, kernelHeadersArm
+}:
+
+assert langC;
+
+stdenv.mkDerivation {
+  name = "gcc-4.0.2-arm";
+  builder = ./builder.sh;
+  src = fetchurl {
+    url = ftp://ftp.nluug.nl/pub/gnu/gcc/gcc-4.0.2/gcc-core-4.0.2.tar.bz2;
+    sha256 = "02fxh0asflm8825w23l2jq1wvs7hbnam0jayrivg7zdv2ifnc0rc";
+  };
+  # !!! apply only if noSysDirs is set
+  patches = [./no-sys-dirs.patch ./gcc-inhibit.patch];
+  inherit noSysDirs langC langCC langF77 profiledCompiler;
+  buildInputs = [binutilsArm];
+  inherit kernelHeadersArm binutilsArm;
+  platform = "arm-linux";
+}
+---
+
+The builder.sh for a cross-compiler. Note that the binutils are prefixed
+with the architecture name, so arm-linux-ld instead of ld, etc. This is
+necessary because when we cross-compile a lot of programs look for these
+tools with these specific names. The standard gcc-wrapper does not take this
+into account yet.
+
+---
+source $stdenv/setup
+
+
+export NIX_FIXINC_DUMMY=$NIX_BUILD_TOP/dummy
+mkdir $NIX_FIXINC_DUMMY
+
+
+if test "$noSysDirs" = "1"; then
+
+    if test "$noSysDirs" = "1"; then
+        # Figure out what extra flags to pass to the gcc compilers
+        # being generated to make sure that they use our glibc.
+        if test -e $NIX_CC/nix-support/orig-glibc; then
+            glibc=$(cat $NIX_CC/nix-support/orig-glibc)
+            # Ugh.  Copied from gcc-wrapper/builder.sh.  We can't just
+            # source in $NIX_CC/nix-support/add-flags, since that
+            # would cause *this* GCC to be linked against the
+            # *previous* GCC.  Need some more modularity there.
+            extraCFlags="-B$glibc/lib -isystem $glibc/include"
+            extraLDFlags="-B$glibc/lib -L$glibc/lib -Wl,-s \
+              -Wl,-dynamic-linker,$glibc/lib/ld-linux.so.2"
+
+            # Oh, what a hack.  I should be shot for this.
+            # In stage 1, we should link against the previous GCC, but
+            # not afterwards.  Otherwise we retain a dependency.
+            # However, ld-wrapper, which adds the linker flags for the
+            # previous GCC, is also used in stage 2/3.  We can prevent
+            # it from adding them by NIX_GLIBC_FLAGS_SET, but then
+            # gcc-wrapper will also not add them, thereby causing
+            # stage 1 to fail.  So we use a trick to only set the
+            # flags in gcc-wrapper.
+            hook=$(pwd)/ld-wrapper-hook
+            echo "NIX_GLIBC_FLAGS_SET=1" > $hook
+            export NIX_LD_WRAPPER_START_HOOK=$hook
+        fi
+
+        export NIX_EXTRA_CFLAGS=$extraCFlags
+        export NIX_EXTRA_LDFLAGS=$extraLDFlags
+        export CFLAGS=$extraCFlags
+        export CXXFLAGS=$extraCFlags
+        export LDFLAGS=$extraLDFlags
+    fi
+
+else
+    patches=""
+fi
+
+
+preConfigure=preConfigure
+preConfigure() {
+    
+    # Determine the frontends to build.
+    langs="c"
+    if test -n "$langCC"; then
+        langs="$langs,c++"
+    fi
+    if test -n "$langF77"; then
+        langs="$langs,f77"
+    fi
+
+    # Cross compiler evilness
+    mkdir -p $out
+    mkdir -p $out/arm-linux
+    mkdir -p $out/arm-linux/bin
+    ln -s $binutilsArm/arm-linux/bin/as $out/arm-linux/bin/as
+    ln -s $binutilsArm/arm-linux/bin/ld $out/arm-linux/bin/ld
+    ln -s $binutilsArm/arm-linux/bin/ar $out/arm-linux/bin/ar
+    ln -s $binutilsArm/arm-linux/bin/ranlib $out/arm-linux/bin/ranlib
+
+    # Perform the build in a different directory.
+    mkdir ../build
+    cd ../build
+
+    configureScript=../$sourceRoot/configure
+    configureFlags="--enable-languages=$langs --target=$platform --disable-threads --disable-libmudflap --disable-shared --with-headers=$kernelHeadersArm/include --disable-multilib"
+}
+
+
+postInstall=postInstall
+postInstall() {
+    # Remove precompiled headers for now.  They are very big and
+    # probably not very useful yet.
+    find $out/include -name "*.gch" -exec rm -rf {} \; -prune
+
+    # Remove `fixincl' to prevent a retained dependency on the
+    # previous gcc.
+    rm -rf $out/libexec/gcc/*/*/install-tools
+}
+
+
+#if test -z "$profiledCompiler"; then
+    #makeFlags="bootstrap"
+#else    
+    #makeFlags="profiledbootstrap"
+#fi
+
+genericBuild
+---
+
+Step 4: build a C library for the target platform.
+
+The previous steps are enough to compile a C library. In our case we take
+uClibc. It's intended to be a small sized replacement for glibc. It is widely
+used in embedded environments.
+
+...
+
+Step 5: Build a compiler to link with the newly built C library.
+
+...
+
+If we restrict the compiler to just C programs it is relatively easy,
+since we only need to wrap the GCC we built in the previous step with all
+the right tools and the right C library. Successfully compiled programs with
+this compiler and verified to be working on a HP Jornada 820 running Linux
+are "patch", "make" and "wget".
+
+If we want to build C++ programs it gets a lot more difficult. GCC has a
+three step compilation process. In the first step a simple compiler, called
+xgcc, that can compile only C programs is built. With that compiler it
+compiles itself two more times: one time to build a full compiler, and another
+time to build a full compiler once again with the freshly built compiler from
+step 2. In the second and third step support for C++ is compiled, if this
+is configured.
+
+One of the libraries that has to be built for C++ support step is libstdc++.
+This library uses xgcc, even when cross compiling, since libstdc++ has to be
+compiled for arm-linux.
+
+One of the compiler flags that GCC uses for this compiler is called X_CFLAGS.
+This is used by the Nix build process to set the dynamic linker, glibc
+in the case of i686-linux using the default Nix packages collection.
+
+Obiously, since we need to compile libstc++ for arm-linux with uClibc linking
+will not be done correctly: you can't link object files built for arm-linux
+with a glibc built for i686-linux.
+
+Setting X_CFLAGS to use the uClibc libraries and dynamic linker will fail
+too. Earlier on in the build process these flags are used to compile important
+files like libgcc.a by the host system gcc, which does need to be linked
+to glibc. To make this work correctly you will need to carefully juggle
+with compilation flags. This is still work in progress for Nix.
+
+
+---
+
+After successfully completing the whole toolchain you can start building
+packages with the newly built tools. To make everything build correctly
+you will need a stdenv for your target platform. Setting up this platform
+will take some effort. Right now there is a very experimental setup for
+arm-linux, which needs to be cleaned up before it is production ready.
+
+Please note that many packages are not well suited for cross-compilation.
+Even though the package itself might be very well portable often the
+buildscripts are not. One thing that we have seen that causes frequent
+build failures is the use of the LD variable. This is often set to 'ld'
+and not $(CROSS)-ld.
diff --git a/nixpkgs/doc/overlays.xml b/nixpkgs/doc/overlays.xml
new file mode 100644
index 000000000000..bff2339ca933
--- /dev/null
+++ b/nixpkgs/doc/overlays.xml
@@ -0,0 +1,195 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-overlays">
+ <title>Overlays</title>
+ <para>
+  This chapter describes how to extend and change Nixpkgs using overlays.
+  Overlays are used to add layers in the fixed-point used by Nixpkgs to compose
+  the set of all packages.
+ </para>
+ <para>
+  Nixpkgs can be configured with a list of overlays, which are applied in
+  order. This means that the order of the overlays can be significant if
+  multiple layers override the same package.
+ </para>
+<!--============================================================-->
+ <section xml:id="sec-overlays-install">
+  <title>Installing overlays</title>
+
+  <para>
+   The list of overlays can be set either explicitly in a Nix expression, or
+   through <literal>&lt;nixpkgs-overlays></literal> or user configuration
+   files.
+  </para>
+
+  <section xml:id="sec-overlays-argument">
+   <title>Set overlays in NixOS or Nix expressions</title>
+
+   <para>
+    On a NixOS system the value of the <literal>nixpkgs.overlays</literal>
+    option, if present, is passed to the system Nixpkgs directly as an
+    argument. Note that this does not affect the overlays for non-NixOS
+    operations (e.g. <literal>nix-env</literal>), which are
+    <link xlink:href="#sec-overlays-lookup">looked</link> up independently.
+   </para>
+
+   <para>
+    The list of overlays can be passed explicitly when importing nixpkgs, for
+    example <literal>import &lt;nixpkgs> { overlays = [ overlay1 overlay2 ];
+    }</literal>.
+   </para>
+
+   <para>
+    Further overlays can be added by calling the <literal>pkgs.extend</literal>
+    or <literal>pkgs.appendOverlays</literal>, although it is often preferable
+    to avoid these functions, because they recompute the Nixpkgs fixpoint,
+    which is somewhat expensive to do.
+   </para>
+  </section>
+
+  <section xml:id="sec-overlays-lookup">
+   <title>Install overlays via configuration lookup</title>
+
+   <para>
+    The list of overlays is determined as follows.
+   </para>
+
+   <para>
+    <orderedlist>
+     <listitem>
+      <para>
+       First, if an
+       <link xlink:href="#sec-overlays-argument"><varname>overlays</varname>
+       argument</link> to the Nixpkgs function itself is given, then that is
+       used and no path lookup will be performed.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       Otherwise, if the Nix path entry
+       <literal>&lt;nixpkgs-overlays></literal> exists, we look for overlays at
+       that path, as described below.
+      </para>
+      <para>
+       See the section on <literal>NIX_PATH</literal> in the Nix manual for
+       more details on how to set a value for
+       <literal>&lt;nixpkgs-overlays>.</literal>
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       If one of <filename>~/.config/nixpkgs/overlays.nix</filename> and
+       <filename>~/.config/nixpkgs/overlays/</filename> exists, then we look
+       for overlays at that path, as described below. It is an error if both
+       exist.
+      </para>
+     </listitem>
+    </orderedlist>
+   </para>
+
+   <para>
+    If we are looking for overlays at a path, then there are two cases:
+    <itemizedlist>
+     <listitem>
+      <para>
+       If the path is a file, then the file is imported as a Nix expression and
+       used as the list of overlays.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       If the path is a directory, then we take the content of the directory,
+       order it lexicographically, and attempt to interpret each as an overlay
+       by:
+       <itemizedlist>
+        <listitem>
+         <para>
+          Importing the file, if it is a <literal>.nix</literal> file.
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          Importing a top-level <filename>default.nix</filename> file, if it is
+          a directory.
+         </para>
+        </listitem>
+       </itemizedlist>
+      </para>
+     </listitem>
+    </itemizedlist>
+   </para>
+
+   <para>
+    Because overlays that are set in NixOS configuration do not affect
+    non-NixOS operations such as <literal>nix-env</literal>, the
+    <filename>overlays.nix</filename> option provides a convenient way to use
+    the same overlays for a NixOS system configuration and user configuration:
+    the same file can be used as <filename>overlays.nix</filename> and imported
+    as the value of <literal>nixpkgs.overlays</literal>.
+   </para>
+
+<!-- TODO: Example of sharing overlays between NixOS configuration
+     and configuration lookup. Also reference the example
+     from the sec-overlays-argument paragraph about NixOS.
+ -->
+  </section>
+ </section>
+<!--============================================================-->
+ <section xml:id="sec-overlays-definition">
+  <title>Defining overlays</title>
+
+  <para>
+   Overlays are Nix functions which accept two arguments, conventionally called
+   <varname>self</varname> and <varname>super</varname>, and return a set of
+   packages. For example, the following is a valid overlay.
+  </para>
+
+<programlisting>
+self: super:
+
+{
+  boost = super.boost.override {
+    python = self.python3;
+  };
+  rr = super.callPackage ./pkgs/rr {
+    stdenv = self.stdenv_32bit;
+  };
+}
+</programlisting>
+
+  <para>
+   The first argument (<varname>self</varname>) corresponds to the final
+   package set. You should use this set for the dependencies of all packages
+   specified in your overlay. For example, all the dependencies of
+   <varname>rr</varname> in the example above come from
+   <varname>self</varname>, as well as the overridden dependencies used in the
+   <varname>boost</varname> override.
+  </para>
+
+  <para>
+   The second argument (<varname>super</varname>) corresponds to the result of
+   the evaluation of the previous stages of Nixpkgs. It does not contain any of
+   the packages added by the current overlay, nor any of the following
+   overlays. This set should be used either to refer to packages you wish to
+   override, or to access functions defined in Nixpkgs. For example, the
+   original recipe of <varname>boost</varname> in the above example, comes from
+   <varname>super</varname>, as well as the <varname>callPackage</varname>
+   function.
+  </para>
+
+  <para>
+   The value returned by this function should be a set similar to
+   <filename>pkgs/top-level/all-packages.nix</filename>, containing overridden
+   and/or new packages.
+  </para>
+
+  <para>
+   Overlays are similar to other methods for customizing Nixpkgs, in particular
+   the <literal>packageOverrides</literal> attribute described in
+   <xref linkend="sec-modify-via-packageOverrides"/>. Indeed,
+   <literal>packageOverrides</literal> acts as an overlay with only the
+   <varname>super</varname> argument. It is therefore appropriate for basic
+   use, but overlays are more powerful and easier to distribute.
+  </para>
+ </section>
+</chapter>
diff --git a/nixpkgs/doc/overrides.css b/nixpkgs/doc/overrides.css
new file mode 100644
index 000000000000..4c7d4a31be2d
--- /dev/null
+++ b/nixpkgs/doc/overrides.css
@@ -0,0 +1,9 @@
+.docbook .xref img[src^=images\/callouts\/],
+.screen img,
+.programlisting img {
+    width: 1em;
+}
+
+.calloutlist img {
+    width: 1.5em;
+}
diff --git a/nixpkgs/doc/package-notes.xml b/nixpkgs/doc/package-notes.xml
new file mode 100644
index 000000000000..803d343aa096
--- /dev/null
+++ b/nixpkgs/doc/package-notes.xml
@@ -0,0 +1,893 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-package-notes">
+ <title>Package Notes</title>
+ <para>
+  This chapter contains information about how to use and maintain the Nix
+  expressions for a number of specific packages, such as the Linux kernel or
+  X.org.
+ </para>
+<!--============================================================-->
+ <section xml:id="sec-linux-kernel">
+  <title>Linux kernel</title>
+
+  <para>
+   The Nix expressions to build the Linux kernel are in
+   <link
+xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/os-specific/linux/kernel"><filename>pkgs/os-specific/linux/kernel</filename></link>.
+  </para>
+
+  <para>
+   The function that builds the kernel has an argument
+   <varname>kernelPatches</varname> which should be a list of <literal>{name,
+   patch, extraConfig}</literal> attribute sets, where <varname>name</varname>
+   is the name of the patch (which is included in the kernel’s
+   <varname>meta.description</varname> attribute), <varname>patch</varname> is
+   the patch itself (possibly compressed), and <varname>extraConfig</varname>
+   (optional) is a string specifying extra options to be concatenated to the
+   kernel configuration file (<filename>.config</filename>).
+  </para>
+
+  <para>
+   The kernel derivation exports an attribute <varname>features</varname>
+   specifying whether optional functionality is or isn’t enabled. This is
+   used in NixOS to implement kernel-specific behaviour. For instance, if the
+   kernel has the <varname>iwlwifi</varname> feature (i.e. has built-in support
+   for Intel wireless chipsets), then NixOS doesn’t have to build the
+   external <varname>iwlwifi</varname> package:
+<programlisting>
+modulesTree = [kernel]
+  ++ pkgs.lib.optional (!kernel.features ? iwlwifi) kernelPackages.iwlwifi
+  ++ ...;
+</programlisting>
+  </para>
+
+  <para>
+   How to add a new (major) version of the Linux kernel to Nixpkgs:
+   <orderedlist>
+    <listitem>
+     <para>
+      Copy the old Nix expression (e.g. <filename>linux-2.6.21.nix</filename>)
+      to the new one (e.g. <filename>linux-2.6.22.nix</filename>) and update
+      it.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Add the new kernel to <filename>all-packages.nix</filename> (e.g., create
+      an attribute <varname>kernel_2_6_22</varname>).
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Now we’re going to update the kernel configuration. First unpack the
+      kernel. Then for each supported platform (<literal>i686</literal>,
+      <literal>x86_64</literal>, <literal>uml</literal>) do the following:
+      <orderedlist>
+       <listitem>
+        <para>
+         Make an copy from the old config (e.g.
+         <filename>config-2.6.21-i686-smp</filename>) to the new one (e.g.
+         <filename>config-2.6.22-i686-smp</filename>).
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Copy the config file for this platform (e.g.
+         <filename>config-2.6.22-i686-smp</filename>) to
+         <filename>.config</filename> in the kernel source tree.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Run <literal>make oldconfig
+         ARCH=<replaceable>{i386,x86_64,um}</replaceable></literal> and answer
+         all questions. (For the uml configuration, also add
+         <literal>SHELL=bash</literal>.) Make sure to keep the configuration
+         consistent between platforms (i.e. don’t enable some feature on
+         <literal>i686</literal> and disable it on <literal>x86_64</literal>).
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         If needed you can also run <literal>make menuconfig</literal>:
+<screen>
+$ nix-env -i ncurses
+$ export NIX_CFLAGS_LINK=-lncurses
+$ make menuconfig ARCH=<replaceable>arch</replaceable></screen>
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Copy <filename>.config</filename> over the new config file (e.g.
+         <filename>config-2.6.22-i686-smp</filename>).
+        </para>
+       </listitem>
+      </orderedlist>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Test building the kernel: <literal>nix-build -A kernel_2_6_22</literal>.
+      If it compiles, ship it! For extra credit, try booting NixOS with it.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      It may be that the new kernel requires updating the external kernel
+      modules and kernel-dependent packages listed in the
+      <varname>linuxPackagesFor</varname> function in
+      <filename>all-packages.nix</filename> (such as the NVIDIA drivers, AUFS,
+      etc.). If the updated packages aren’t backwards compatible with older
+      kernels, you may need to keep the older versions around.
+     </para>
+    </listitem>
+   </orderedlist>
+  </para>
+ </section>
+<!--============================================================-->
+ <section xml:id="sec-xorg">
+  <title>X.org</title>
+
+  <para>
+   The Nix expressions for the X.org packages reside in
+   <filename>pkgs/servers/x11/xorg/default.nix</filename>. This file is
+   automatically generated from lists of tarballs in an X.org release. As such
+   it should not be modified directly; rather, you should modify the lists, the
+   generator script or the file
+   <filename>pkgs/servers/x11/xorg/overrides.nix</filename>, in which you can
+   override or add to the derivations produced by the generator.
+  </para>
+
+  <para>
+   The generator is invoked as follows:
+<screen>
+$ cd pkgs/servers/x11/xorg
+$ cat tarballs-7.5.list extra.list old.list \
+  | perl ./generate-expr-from-tarballs.pl
+</screen>
+   For each of the tarballs in the <filename>.list</filename> files, the script
+   downloads it, unpacks it, and searches its <filename>configure.ac</filename>
+   and <filename>*.pc.in</filename> files for dependencies. This information is
+   used to generate <filename>default.nix</filename>. The generator caches
+   downloaded tarballs between runs. Pay close attention to the <literal>NOT
+   FOUND: <replaceable>name</replaceable></literal> messages at the end of the
+   run, since they may indicate missing dependencies. (Some might be optional
+   dependencies, however.)
+  </para>
+
+  <para>
+   A file like <filename>tarballs-7.5.list</filename> contains all tarballs in
+   a X.org release. It can be generated like this:
+<screen>
+$ export i="mirror://xorg/X11R7.4/src/everything/"
+$ cat $(PRINT_PATH=1 nix-prefetch-url $i | tail -n 1) \
+  | perl -e 'while (&lt;>) { if (/(href|HREF)="([^"]*.bz2)"/) { print "$ENV{'i'}$2\n"; }; }' \
+  | sort > tarballs-7.4.list
+</screen>
+   <filename>extra.list</filename> contains libraries that aren’t part of
+   X.org proper, but are closely related to it, such as
+   <literal>libxcb</literal>. <filename>old.list</filename> contains some
+   packages that were removed from X.org, but are still needed by some people
+   or by other packages (such as <varname>imake</varname>).
+  </para>
+
+  <para>
+   If the expression for a package requires derivation attributes that the
+   generator cannot figure out automatically (say, <varname>patches</varname>
+   or a <varname>postInstall</varname> hook), you should modify
+   <filename>pkgs/servers/x11/xorg/overrides.nix</filename>.
+  </para>
+ </section>
+<!--============================================================-->
+<!--
+<section xml:id="sec-package-notes-gnome">
+  <title>Gnome</title>
+  <para>* Expression is auto-generated</para>
+  <para>* How to update</para>
+</section>
+-->
+<!--============================================================-->
+<!--
+<section xml:id="sec-package-notes-gcc">
+  <title>GCC</title>
+  <para>…</para>
+</section>
+-->
+<!--============================================================-->
+ <section xml:id="sec-eclipse">
+  <title>Eclipse</title>
+
+  <para>
+   The Nix expressions related to the Eclipse platform and IDE are in
+   <link xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/editors/eclipse"><filename>pkgs/applications/editors/eclipse</filename></link>.
+  </para>
+
+  <para>
+   Nixpkgs provides a number of packages that will install Eclipse in its
+   various forms. These range from the bare-bones Eclipse Platform to the more
+   fully featured Eclipse SDK or Scala-IDE packages and multiple version are
+   often available. It is possible to list available Eclipse packages by
+   issuing the command:
+<screen>
+$ nix-env -f '&lt;nixpkgs&gt;' -qaP -A eclipses --description
+</screen>
+   Once an Eclipse variant is installed it can be run using the
+   <command>eclipse</command> command, as expected. From within Eclipse it is
+   then possible to install plugins in the usual manner by either manually
+   specifying an Eclipse update site or by installing the Marketplace Client
+   plugin and using it to discover and install other plugins. This installation
+   method provides an Eclipse installation that closely resemble a manually
+   installed Eclipse.
+  </para>
+
+  <para>
+   If you prefer to install plugins in a more declarative manner then Nixpkgs
+   also offer a number of Eclipse plugins that can be installed in an
+   <emphasis>Eclipse environment</emphasis>. This type of environment is
+   created using the function <varname>eclipseWithPlugins</varname> found
+   inside the <varname>nixpkgs.eclipses</varname> attribute set. This function
+   takes as argument <literal>{ eclipse, plugins ? [], jvmArgs ? [] }</literal>
+   where <varname>eclipse</varname> is a one of the Eclipse packages described
+   above, <varname>plugins</varname> is a list of plugin derivations, and
+   <varname>jvmArgs</varname> is a list of arguments given to the JVM running
+   the Eclipse. For example, say you wish to install the latest Eclipse
+   Platform with the popular Eclipse Color Theme plugin and also allow Eclipse
+   to use more RAM. You could then add
+<screen>
+packageOverrides = pkgs: {
+  myEclipse = with pkgs.eclipses; eclipseWithPlugins {
+    eclipse = eclipse-platform;
+    jvmArgs = [ "-Xmx2048m" ];
+    plugins = [ plugins.color-theme ];
+  };
+}
+</screen>
+   to your Nixpkgs configuration
+   (<filename>~/.config/nixpkgs/config.nix</filename>) and install it by
+   running <command>nix-env -f '&lt;nixpkgs&gt;' -iA myEclipse</command> and
+   afterward run Eclipse as usual. It is possible to find out which plugins are
+   available for installation using <varname>eclipseWithPlugins</varname> by
+   running
+<screen>
+$ nix-env -f '&lt;nixpkgs&gt;' -qaP -A eclipses.plugins --description
+</screen>
+  </para>
+
+  <para>
+   If there is a need to install plugins that are not available in Nixpkgs then
+   it may be possible to define these plugins outside Nixpkgs using the
+   <varname>buildEclipseUpdateSite</varname> and
+   <varname>buildEclipsePlugin</varname> functions found in the
+   <varname>nixpkgs.eclipses.plugins</varname> attribute set. Use the
+   <varname>buildEclipseUpdateSite</varname> function to install a plugin
+   distributed as an Eclipse update site. This function takes <literal>{ name,
+   src }</literal> as argument where <literal>src</literal> indicates the
+   Eclipse update site archive. All Eclipse features and plugins within the
+   downloaded update site will be installed. When an update site archive is not
+   available then the <varname>buildEclipsePlugin</varname> function can be
+   used to install a plugin that consists of a pair of feature and plugin JARs.
+   This function takes an argument <literal>{ name, srcFeature, srcPlugin
+   }</literal> where <literal>srcFeature</literal> and
+   <literal>srcPlugin</literal> are the feature and plugin JARs, respectively.
+  </para>
+
+  <para>
+   Expanding the previous example with two plugins using the above functions we
+   have
+<screen>
+packageOverrides = pkgs: {
+  myEclipse = with pkgs.eclipses; eclipseWithPlugins {
+    eclipse = eclipse-platform;
+    jvmArgs = [ "-Xmx2048m" ];
+    plugins = [
+      plugins.color-theme
+      (plugins.buildEclipsePlugin {
+        name = "myplugin1-1.0";
+        srcFeature = fetchurl {
+          url = "http://…/features/myplugin1.jar";
+          sha256 = "123…";
+        };
+        srcPlugin = fetchurl {
+          url = "http://…/plugins/myplugin1.jar";
+          sha256 = "123…";
+        };
+      });
+      (plugins.buildEclipseUpdateSite {
+        name = "myplugin2-1.0";
+        src = fetchurl {
+          stripRoot = false;
+          url = "http://…/myplugin2.zip";
+          sha256 = "123…";
+        };
+      });
+    ];
+  };
+}
+</screen>
+  </para>
+ </section>
+ <section xml:id="sec-elm">
+  <title>Elm</title>
+
+  <para>
+   The Nix expressions for Elm reside in
+   <filename>pkgs/development/compilers/elm</filename>. They are generated
+   automatically by <command>update-elm.rb</command> script. One should specify
+   versions of Elm packages inside the script, clear the
+   <filename>packages</filename> directory and run the script from inside it.
+   <literal>elm-reactor</literal> is special because it also has Elm package
+   dependencies. The process is not automated very much for now -- you should
+   get the <literal>elm-reactor</literal> source tree (e.g. with
+   <command>nix-shell</command>) and run <command>elm2nix.rb</command> inside
+   it. Place the resulting <filename>package.nix</filename> file into
+   <filename>packages/elm-reactor-elm.nix</filename>.
+  </para>
+ </section>
+ <section xml:id="sec-shell-helpers">
+  <title>Interactive shell helpers</title>
+
+  <para>
+   Some packages provide the shell integration to be more useful. But unlike
+   other systems, nix doesn't have a standard share directory location. This is
+   why a bunch <command>PACKAGE-share</command> scripts are shipped that print
+   the location of the corresponding shared folder. Current list of such
+   packages is as following:
+   <itemizedlist>
+    <listitem>
+     <para>
+      <literal>autojump</literal>: <command>autojump-share</command>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      <literal>fzf</literal>: <command>fzf-share</command>
+     </para>
+    </listitem>
+   </itemizedlist>
+   E.g. <literal>autojump</literal> can then used in the .bashrc like this:
+<screen>
+  source "$(autojump-share)/autojump.bash"
+</screen>
+  </para>
+ </section>
+ <section xml:id="sec-steam">
+  <title>Steam</title>
+
+  <section xml:id="sec-steam-nix">
+   <title>Steam in Nix</title>
+
+   <para>
+    Steam is distributed as a <filename>.deb</filename> file, for now only as
+    an i686 package (the amd64 package only has documentation). When unpacked,
+    it has a script called <filename>steam</filename> that in ubuntu (their
+    target distro) would go to <filename>/usr/bin </filename>. When run for the
+    first time, this script copies some files to the user's home, which include
+    another script that is the ultimate responsible for launching the steam
+    binary, which is also in $HOME.
+   </para>
+
+   <para>
+    Nix problems and constraints:
+    <itemizedlist>
+     <listitem>
+      <para>
+       We don't have <filename>/bin/bash</filename> and many scripts point
+       there. Similarly for <filename>/usr/bin/python</filename> .
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       We don't have the dynamic loader in <filename>/lib </filename>.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       The <filename>steam.sh</filename> script in $HOME can not be patched, as
+       it is checked and rewritten by steam.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       The steam binary cannot be patched, it's also checked.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </para>
+
+   <para>
+    The current approach to deploy Steam in NixOS is composing a FHS-compatible
+    chroot environment, as documented
+    <link xlink:href="http://sandervanderburg.blogspot.nl/2013/09/composing-fhs-compatible-chroot.html">here</link>.
+    This allows us to have binaries in the expected paths without disrupting
+    the system, and to avoid patching them to work in a non FHS environment.
+   </para>
+  </section>
+
+  <section xml:id="sec-steam-play">
+   <title>How to play</title>
+
+   <para>
+    For 64-bit systems it's important to have
+<programlisting>hardware.opengl.driSupport32Bit = true;</programlisting>
+    in your <filename>/etc/nixos/configuration.nix</filename>. You'll also need
+<programlisting>hardware.pulseaudio.support32Bit = true;</programlisting>
+    if you are using PulseAudio - this will enable 32bit ALSA apps integration.
+    To use the Steam controller or other Steam supported controllers such as
+    the DualShock 4 or Nintendo Switch Pro, you need to add
+<programlisting>hardware.steam-hardware.enable = true;</programlisting>
+    to your configuration.
+   </para>
+  </section>
+
+  <section xml:id="sec-steam-troub">
+   <title>Troubleshooting</title>
+
+   <para>
+    <variablelist>
+     <varlistentry>
+      <term>
+       Steam fails to start. What do I do?
+      </term>
+      <listitem>
+       <para>
+        Try to run
+<programlisting>strace steam</programlisting>
+        to see what is causing steam to fail.
+       </para>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       Using the FOSS Radeon or nouveau (nvidia) drivers
+      </term>
+      <listitem>
+       <itemizedlist>
+        <listitem>
+         <para>
+          The <literal>newStdcpp</literal> parameter was removed since NixOS
+          17.09 and should not be needed anymore.
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          Steam ships statically linked with a version of libcrypto that
+          conflics with the one dynamically loaded by radeonsi_dri.so. If you
+          get the error
+<programlisting>steam.sh: line 713: 7842 Segmentation fault (core dumped)</programlisting>
+          have a look at
+          <link xlink:href="https://github.com/NixOS/nixpkgs/pull/20269">this
+          pull request</link>.
+         </para>
+        </listitem>
+       </itemizedlist>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       Java
+      </term>
+      <listitem>
+       <orderedlist>
+        <listitem>
+         <para>
+          There is no java in steam chrootenv by default. If you get a message
+          like
+<programlisting>/home/foo/.local/share/Steam/SteamApps/common/towns/towns.sh: line 1: java: command not found</programlisting>
+          You need to add
+<programlisting> steam.override { withJava = true; };</programlisting>
+          to your configuration.
+         </para>
+        </listitem>
+       </orderedlist>
+      </listitem>
+     </varlistentry>
+    </variablelist>
+   </para>
+  </section>
+
+  <section xml:id="sec-steam-run">
+   <title>steam-run</title>
+
+   <para>
+    The FHS-compatible chroot used for steam can also be used to run other
+    linux games that expect a FHS environment. To do it, add
+<programlisting>pkgs.(steam.override {
+          nativeOnly = true;
+          newStdcpp = true;
+        }).run</programlisting>
+    to your configuration, rebuild, and run the game with
+<programlisting>steam-run ./foo</programlisting>
+   </para>
+  </section>
+ </section>
+ <section xml:id="sec-emacs">
+  <title>Emacs</title>
+
+  <section xml:id="sec-emacs-config">
+   <title>Configuring Emacs</title>
+
+   <para>
+    The Emacs package comes with some extra helpers to make it easier to
+    configure. <varname>emacsWithPackages</varname> allows you to manage
+    packages from ELPA. This means that you will not have to install that
+    packages from within Emacs. For instance, if you wanted to use
+    <literal>company</literal>, <literal>counsel</literal>,
+    <literal>flycheck</literal>, <literal>ivy</literal>,
+    <literal>magit</literal>, <literal>projectile</literal>, and
+    <literal>use-package</literal> you could use this as a
+    <filename>~/.config/nixpkgs/config.nix</filename> override:
+   </para>
+
+<screen>
+{
+  packageOverrides = pkgs: with pkgs; {
+    myEmacs = emacsWithPackages (epkgs: (with epkgs.melpaStablePackages; [
+      company
+      counsel
+      flycheck
+      ivy
+      magit
+      projectile
+      use-package
+    ]));
+  }
+}
+</screen>
+
+   <para>
+    You can install it like any other packages via <command>nix-env -iA
+    myEmacs</command>. However, this will only install those packages. It will
+    not <literal>configure</literal> them for us. To do this, we need to
+    provide a configuration file. Luckily, it is possible to do this from
+    within Nix! By modifying the above example, we can make Emacs load a custom
+    config file. The key is to create a package that provide a
+    <filename>default.el</filename> file in
+    <filename>/share/emacs/site-start/</filename>. Emacs knows to load this
+    file automatically when it starts.
+   </para>
+
+<screen>
+{
+  packageOverrides = pkgs: with pkgs; rec {
+    myEmacsConfig = writeText "default.el" ''
+;; initialize package
+
+(require 'package)
+(package-initialize 'noactivate)
+(eval-when-compile
+  (require 'use-package))
+
+;; load some packages
+
+(use-package company
+  :bind ("&lt;C-tab&gt;" . company-complete)
+  :diminish company-mode
+  :commands (company-mode global-company-mode)
+  :defer 1
+  :config
+  (global-company-mode))
+
+(use-package counsel
+  :commands (counsel-descbinds)
+  :bind (([remap execute-extended-command] . counsel-M-x)
+         ("C-x C-f" . counsel-find-file)
+         ("C-c g" . counsel-git)
+         ("C-c j" . counsel-git-grep)
+         ("C-c k" . counsel-ag)
+         ("C-x l" . counsel-locate)
+         ("M-y" . counsel-yank-pop)))
+
+(use-package flycheck
+  :defer 2
+  :config (global-flycheck-mode))
+
+(use-package ivy
+  :defer 1
+  :bind (("C-c C-r" . ivy-resume)
+         ("C-x C-b" . ivy-switch-buffer)
+         :map ivy-minibuffer-map
+         ("C-j" . ivy-call))
+  :diminish ivy-mode
+  :commands ivy-mode
+  :config
+  (ivy-mode 1))
+
+(use-package magit
+  :defer
+  :if (executable-find "git")
+  :bind (("C-x g" . magit-status)
+         ("C-x G" . magit-dispatch-popup))
+  :init
+  (setq magit-completing-read-function 'ivy-completing-read))
+
+(use-package projectile
+  :commands projectile-mode
+  :bind-keymap ("C-c p" . projectile-command-map)
+  :defer 5
+  :config
+  (projectile-global-mode))
+    '';
+    myEmacs = emacsWithPackages (epkgs: (with epkgs.melpaStablePackages; [
+      (runCommand "default.el" {} ''
+mkdir -p $out/share/emacs/site-lisp
+cp ${myEmacsConfig} $out/share/emacs/site-lisp/default.el
+'')
+      company
+      counsel
+      flycheck
+      ivy
+      magit
+      projectile
+      use-package
+    ]));
+  };
+}
+</screen>
+
+   <para>
+    This provides a fairly full Emacs start file. It will load in addition to
+    the user's presonal config. You can always disable it by passing
+    <command>-q</command> to the Emacs command.
+   </para>
+
+   <para>
+    Sometimes <varname>emacsWithPackages</varname> is not enough, as this
+    package set has some priorities imposed on packages (with the lowest
+    priority assigned to Melpa Unstable, and the highest for packages manually
+    defined in <filename>pkgs/top-level/emacs-packages.nix</filename>). But you
+    can't control this priorities when some package is installed as a
+    dependency. You can override it on per-package-basis, providing all the
+    required dependencies manually - but it's tedious and there is always a
+    possibility that an unwanted dependency will sneak in through some other
+    package. To completely override such a package you can use
+    <varname>overrideScope'</varname>.
+   </para>
+
+<screen>
+overrides = self: super: rec {
+  haskell-mode = self.melpaPackages.haskell-mode;
+  ...
+};
+((emacsPackagesNgGen emacs).overrideScope' overrides).emacsWithPackages (p: with p; [
+  # here both these package will use haskell-mode of our own choice
+  ghc-mod
+  dante
+])
+</screen>
+  </section>
+ </section>
+ <section xml:id="sec-weechat">
+  <title>Weechat</title>
+
+  <para>
+   Weechat can be configured to include your choice of plugins, reducing its
+   closure size from the default configuration which includes all available
+   plugins. To make use of this functionality, install an expression that
+   overrides its configuration such as
+<programlisting>weechat.override {configure = {availablePlugins, ...}: {
+    plugins = with availablePlugins; [ python perl ];
+  }
+}</programlisting>
+   If the <literal>configure</literal> function returns an attrset without the
+   <literal>plugins</literal> attribute, <literal>availablePlugins</literal>
+   will be used automatically.
+  </para>
+
+  <para>
+   The plugins currently available are <literal>python</literal>,
+   <literal>perl</literal>, <literal>ruby</literal>, <literal>guile</literal>,
+   <literal>tcl</literal> and <literal>lua</literal>.
+  </para>
+
+  <para>
+   The python and perl plugins allows the addition of extra libraries. For
+   instance, the <literal>inotify.py</literal> script in weechat-scripts
+   requires D-Bus or libnotify, and the <literal>fish.py</literal> script
+   requires pycrypto. To use these scripts, use the plugin's
+   <literal>withPackages</literal> attribute:
+<programlisting>weechat.override { configure = {availablePlugins, ...}: {
+    plugins = with availablePlugins; [
+            (python.withPackages (ps: with ps; [ pycrypto python-dbus ]))
+        ];
+    };
+}
+</programlisting>
+  </para>
+
+  <para>
+   In order to also keep all default plugins installed, it is possible to use
+   the following method:
+<programlisting>weechat.override { configure = { availablePlugins, ... }: {
+  plugins = builtins.attrValues (availablePlugins // {
+    python = availablePlugins.python.withPackages (ps: with ps; [ pycrypto python-dbus ]);
+  });
+}; }
+</programlisting>
+  </para>
+
+  <para>
+   WeeChat allows to set defaults on startup using the
+   <literal>--run-command</literal>. The <literal>configure</literal> method
+   can be used to pass commands to the program:
+<programlisting>weechat.override {
+  configure = { availablePlugins, ... }: {
+    init = ''
+      /set foo bar
+      /server add freenode chat.freenode.org
+    '';
+  };
+}</programlisting>
+   Further values can be added to the list of commands when running
+   <literal>weechat --run-command "your-commands"</literal>.
+  </para>
+
+  <para>
+   Additionally it's possible to specify scripts to be loaded when starting
+   <literal>weechat</literal>. These will be loaded before the commands from
+   <literal>init</literal>:
+<programlisting>weechat.override {
+  configure = { availablePlugins, ... }: {
+    scripts = with pkgs.weechatScripts; [
+      weechat-xmpp weechat-matrix-bridge wee-slack
+    ];
+    init = ''
+      /set plugins.var.python.jabber.key "val"
+    '':
+  };
+}</programlisting>
+  </para>
+
+  <para>
+   In <literal>nixpkgs</literal> there's a subpackage which contains
+   derivations for WeeChat scripts. Such derivations expect a
+   <literal>passthru.scripts</literal> attribute which contains a list of all
+   scripts inside the store path. Furthermore all scripts have to live in
+   <literal>$out/share</literal>. An exemplary derivation looks like this:
+<programlisting>{ stdenv, fetchurl }:
+
+stdenv.mkDerivation {
+  name = "exemplary-weechat-script";
+  src = fetchurl {
+    url = "https://scripts.tld/your-scripts.tar.gz";
+    sha256 = "...";
+  };
+  passthru.scripts = [ "foo.py" "bar.lua" ];
+  installPhase = ''
+    mkdir $out/share
+    cp foo.py $out/share
+    cp bar.lua $out/share
+  '';
+}</programlisting>
+  </para>
+ </section>
+ <section xml:id="sec-citrix">
+  <title>Citrix Receiver</title>
+
+  <para>
+   The <link xlink:href="https://www.citrix.com/products/receiver/">Citrix
+   Receiver</link> is a remote desktop viewer which provides access to
+   <link xlink:href="https://www.citrix.com/products/xenapp-xendesktop/">XenDesktop</link>
+   installations.
+  </para>
+
+  <section xml:id="sec-citrix-base">
+   <title>Basic usage</title>
+
+   <para>
+    The tarball archive needs to be downloaded manually as the licenses
+    agreements of the vendor need to be accepted first. This is available at
+    the
+    <link xlink:href="https://www.citrix.com/downloads/citrix-receiver/">download
+    page at citrix.com</link>. Then run <literal>nix-prefetch-url
+    file://$PWD/linuxx64-$version.tar.gz</literal>. With the archive available
+    in the store the package can be built and installed with Nix.
+   </para>
+
+   <para>
+    <emphasis>Note: it's recommended to install <literal>Citrix
+    Receiver</literal> using <literal>nix-env -i</literal> or globally to
+    ensure that the <literal>.desktop</literal> files are installed properly
+    into <literal>$XDG_CONFIG_DIRS</literal>. Otherwise it won't be possible to
+    open <literal>.ica</literal> files automatically from the browser to start
+    a Citrix connection.</emphasis>
+   </para>
+  </section>
+
+  <section xml:id="sec-citrix-custom-certs">
+   <title>Custom certificates</title>
+
+   <para>
+    The <literal>Citrix Receiver</literal> in <literal>nixpkgs</literal> trusts
+    several certificates
+    <link xlink:href="https://curl.haxx.se/docs/caextract.html">from the
+    Mozilla database</link> by default. However several companies using Citrix
+    might require their own corporate certificate. On distros with imperative
+    packaging these certs can be stored easily in
+    <link xlink:href="https://developer-docs.citrix.com/projects/receiver-for-linux-command-reference/en/13.7/"><literal>$ICAROOT</literal></link>,
+    however this directory is a store path in <literal>nixpkgs</literal>. In
+    order to work around this issue the package provides a simple mechanism to
+    add custom certificates without rebuilding the entire package using
+    <literal>symlinkJoin</literal>:
+<programlisting>
+<![CDATA[with import <nixpkgs> { config.allowUnfree = true; };
+let extraCerts = [ ./custom-cert-1.pem ./custom-cert-2.pem /* ... */ ]; in
+citrix_receiver.override {
+  inherit extraCerts;
+}]]>
+</programlisting>
+   </para>
+  </section>
+ </section>
+ <section xml:id="sec-ibus-typing-booster">
+  <title>ibus-engines.typing-booster</title>
+
+  <para>
+   This package is an ibus-based completion method to speed up typing.
+  </para>
+
+  <section xml:id="sec-ibus-typing-booster-activate">
+   <title>Activating the engine</title>
+
+   <para>
+    IBus needs to be configured accordingly to activate
+    <literal>typing-booster</literal>. The configuration depends on the desktop
+    manager in use. For detailed instructions, please refer to the
+    <link xlink:href="https://mike-fabian.github.io/ibus-typing-booster/documentation.html">upstream
+    docs</link>.
+   </para>
+
+   <para>
+    On NixOS you need to explicitly enable <literal>ibus</literal> with given
+    engines before customizing your desktop to use
+    <literal>typing-booster</literal>. This can be achieved using the
+    <literal>ibus</literal> module:
+<programlisting>{ pkgs, ... }: {
+  i18n.inputMethod = {
+    enabled = "ibus";
+    ibus.engines = with pkgs.ibus-engines; [ typing-booster ];
+  };
+}</programlisting>
+   </para>
+  </section>
+
+  <section xml:id="sec-ibus-typing-booster-customize-hunspell">
+   <title>Using custom hunspell dictionaries</title>
+
+   <para>
+    The IBus engine is based on <literal>hunspell</literal> to support
+    completion in many languages. By default the dictionaries
+    <literal>de-de</literal>, <literal>en-us</literal>,
+    <literal>es-es</literal>, <literal>it-it</literal>,
+    <literal>sv-se</literal> and <literal>sv-fi</literal> are in use. To add
+    another dictionary, the package can be overridden like this:
+<programlisting>ibus-engines.typing-booster.override {
+  langs = [ "de-at" "en-gb" ];
+}</programlisting>
+   </para>
+
+   <para>
+    <emphasis>Note: each language passed to <literal>langs</literal> must be an
+    attribute name in <literal>pkgs.hunspellDicts</literal>.</emphasis>
+   </para>
+  </section>
+
+  <section xml:id="sec-ibus-typing-booster-emoji-picker">
+   <title>Built-in emoji picker</title>
+
+   <para>
+    The <literal>ibus-engines.typing-booster</literal> package contains a
+    program named <literal>emoji-picker</literal>. To display all emojis
+    correctly, a special font such as <literal>noto-fonts-emoji</literal> is
+    needed:
+   </para>
+
+   <para>
+    On NixOS it can be installed using the following expression:
+<programlisting>{ pkgs, ... }: {
+  fonts.fonts = with pkgs; [ noto-fonts-emoji ];
+}</programlisting>
+   </para>
+  </section>
+ </section>
+</chapter>
diff --git a/nixpkgs/doc/platform-notes.xml b/nixpkgs/doc/platform-notes.xml
new file mode 100644
index 000000000000..6050271dbf6f
--- /dev/null
+++ b/nixpkgs/doc/platform-notes.xml
@@ -0,0 +1,105 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-platform-nodes">
+ <title>Platform Notes</title>
+ <section xml:id="sec-darwin">
+  <title>Darwin (macOS)</title>
+
+  <para>
+   Some common issues when packaging software for Darwin:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     The Darwin <literal>stdenv</literal> uses clang instead of gcc. When
+     referring to the compiler <varname>$CC</varname> or <command>cc</command>
+     will work in both cases. Some builds hardcode gcc/g++ in their build
+     scripts, that can usually be fixed with using something like
+     <literal>makeFlags = [ "CC=cc" ];</literal> or by patching the build
+     scripts.
+    </para>
+<programlisting>
+      stdenv.mkDerivation {
+        name = "libfoo-1.2.3";
+        # ...
+        buildPhase = ''
+          $CC -o hello hello.c
+        '';
+      }
+    </programlisting>
+   </listitem>
+   <listitem>
+    <para>
+     On Darwin, libraries are linked using absolute paths, libraries are
+     resolved by their <literal>install_name</literal> at link time. Sometimes
+     packages won't set this correctly causing the library lookups to fail at
+     runtime. This can be fixed by adding extra linker flags or by running
+     <command>install_name_tool -id</command> during the
+     <function>fixupPhase</function>.
+    </para>
+<programlisting>
+      stdenv.mkDerivation {
+        name = "libfoo-1.2.3";
+        # ...
+        makeFlags = stdenv.lib.optional stdenv.isDarwin "LDFLAGS=-Wl,-install_name,$(out)/lib/libfoo.dylib";
+      }
+    </programlisting>
+   </listitem>
+   <listitem>
+    <para>
+     Even if the libraries are linked using absolute paths and resolved via
+     their <literal>install_name</literal> correctly, tests can sometimes fail
+     to run binaries. This happens because the <varname>checkPhase</varname>
+     runs before the libraries are installed.
+    </para>
+    <para>
+     This can usually be solved by running the tests after the
+     <varname>installPhase</varname> or alternatively by using
+     <varname>DYLD_LIBRARY_PATH</varname>. More information about this variable
+     can be found in the <citerefentry>
+     <refentrytitle>dyld</refentrytitle>
+     <manvolnum>1</manvolnum></citerefentry> manpage.
+    </para>
+<programlisting>
+      dyld: Library not loaded: /nix/store/7hnmbscpayxzxrixrgxvvlifzlxdsdir-jq-1.5-lib/lib/libjq.1.dylib
+      Referenced from: /private/tmp/nix-build-jq-1.5.drv-0/jq-1.5/tests/../jq
+      Reason: image not found
+      ./tests/jqtest: line 5: 75779 Abort trap: 6
+    </programlisting>
+<programlisting>
+      stdenv.mkDerivation {
+        name = "libfoo-1.2.3";
+        # ...
+        doInstallCheck = true;
+        installCheckTarget = "check";
+      }
+    </programlisting>
+   </listitem>
+   <listitem>
+    <para>
+     Some packages assume xcode is available and use <command>xcrun</command>
+     to resolve build tools like <command>clang</command>, etc. This causes
+     errors like <code>xcode-select: error: no developer tools were found at
+     '/Applications/Xcode.app'</code> while the build doesn't actually depend
+     on xcode.
+    </para>
+<programlisting>
+      stdenv.mkDerivation {
+        name = "libfoo-1.2.3";
+        # ...
+        prePatch = ''
+          substituteInPlace Makefile \
+              --replace '/usr/bin/xcrun clang' clang
+        '';
+      }
+    </programlisting>
+    <para>
+     The package <literal>xcbuild</literal> can be used to build projects that
+     really depend on Xcode. However, this replacement is not 100%
+     compatible with Xcode and can occasionally cause issues.
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+</chapter>
diff --git a/nixpkgs/doc/quick-start.xml b/nixpkgs/doc/quick-start.xml
new file mode 100644
index 000000000000..8dd673ed2733
--- /dev/null
+++ b/nixpkgs/doc/quick-start.xml
@@ -0,0 +1,219 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-quick-start">
+ <title>Quick Start to Adding a Package</title>
+ <para>
+  To add a package to Nixpkgs:
+  <orderedlist>
+   <listitem>
+    <para>
+     Checkout the Nixpkgs source tree:
+<screen>
+$ git clone https://github.com/NixOS/nixpkgs
+$ cd nixpkgs</screen>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Find a good place in the Nixpkgs tree to add the Nix expression for your
+     package. For instance, a library package typically goes into
+     <filename>pkgs/development/libraries/<replaceable>pkgname</replaceable></filename>,
+     while a web browser goes into
+     <filename>pkgs/applications/networking/browsers/<replaceable>pkgname</replaceable></filename>.
+     See <xref linkend="sec-organisation" /> for some hints on the tree
+     organisation. Create a directory for your package, e.g.
+<screen>
+$ mkdir pkgs/development/libraries/libfoo</screen>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     In the package directory, create a Nix expression — a piece of code that
+     describes how to build the package. In this case, it should be a
+     <emphasis>function</emphasis> that is called with the package dependencies
+     as arguments, and returns a build of the package in the Nix store. The
+     expression should usually be called <filename>default.nix</filename>.
+<screen>
+$ emacs pkgs/development/libraries/libfoo/default.nix
+$ git add pkgs/development/libraries/libfoo/default.nix</screen>
+    </para>
+    <para>
+     You can have a look at the existing Nix expressions under
+     <filename>pkgs/</filename> to see how it’s done. Here are some good
+     ones:
+     <itemizedlist>
+      <listitem>
+       <para>
+        GNU Hello:
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/hello/default.nix"><filename>pkgs/applications/misc/hello/default.nix</filename></link>.
+        Trivial package, which specifies some <varname>meta</varname>
+        attributes which is good practice.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        GNU cpio:
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/archivers/cpio/default.nix"><filename>pkgs/tools/archivers/cpio/default.nix</filename></link>.
+        Also a simple package. The generic builder in <varname>stdenv</varname>
+        does everything for you. It has no dependencies beyond
+        <varname>stdenv</varname>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        GNU Multiple Precision arithmetic library (GMP):
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/development/libraries/gmp/5.1.x.nix"><filename>pkgs/development/libraries/gmp/5.1.x.nix</filename></link>.
+        Also done by the generic builder, but has a dependency on
+        <varname>m4</varname>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Pan, a GTK-based newsreader:
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/networking/newsreaders/pan/default.nix"><filename>pkgs/applications/networking/newsreaders/pan/default.nix</filename></link>.
+        Has an optional dependency on <varname>gtkspell</varname>, which is
+        only built if <varname>spellCheck</varname> is <literal>true</literal>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Apache HTTPD:
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/servers/http/apache-httpd/2.4.nix"><filename>pkgs/servers/http/apache-httpd/2.4.nix</filename></link>.
+        A bunch of optional features, variable substitutions in the configure
+        flags, a post-install hook, and miscellaneous hackery.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Thunderbird:
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/networking/mailreaders/thunderbird/default.nix"><filename>pkgs/applications/networking/mailreaders/thunderbird/default.nix</filename></link>.
+        Lots of dependencies.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        JDiskReport, a Java utility:
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/misc/jdiskreport/default.nix"><filename>pkgs/tools/misc/jdiskreport/default.nix</filename></link>
+        (and the
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/tools/misc/jdiskreport/builder.sh">builder</link>).
+        Nixpkgs doesn’t have a decent <varname>stdenv</varname> for Java yet
+        so this is pretty ad-hoc.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        XML::Simple, a Perl module:
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/perl-packages.nix"><filename>pkgs/top-level/perl-packages.nix</filename></link>
+        (search for the <varname>XMLSimple</varname> attribute). Most Perl
+        modules are so simple to build that they are defined directly in
+        <filename>perl-packages.nix</filename>; no need to make a separate file
+        for them.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Adobe Reader:
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/adobe-reader/default.nix"><filename>pkgs/applications/misc/adobe-reader/default.nix</filename></link>.
+        Shows how binary-only packages can be supported. In particular the
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/applications/misc/adobe-reader/builder.sh">builder</link>
+        uses <command>patchelf</command> to set the RUNPATH and ELF interpreter
+        of the executables so that the right libraries are found at runtime.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+    <para>
+     Some notes:
+     <itemizedlist>
+      <listitem>
+       <para>
+        All <varname linkend="chap-meta">meta</varname> attributes are
+        optional, but it’s still a good idea to provide at least the
+        <varname>description</varname>, <varname>homepage</varname> and
+        <varname
+          linkend="sec-meta-license">license</varname>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        You can use <command>nix-prefetch-url</command>
+        <replaceable>url</replaceable> to get the
+        SHA-256 hash of source distributions. There are similar commands as
+        <command>nix-prefetch-git</command> and
+        <command>nix-prefetch-hg</command> available in
+        <literal>nix-prefetch-scripts</literal> package.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        A list of schemes for <literal>mirror://</literal> URLs can be found in
+        <link
+          xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/fetchurl/mirrors.nix"><filename>pkgs/build-support/fetchurl/mirrors.nix</filename></link>.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+    <para>
+     The exact syntax and semantics of the Nix expression language, including
+     the built-in function, are described in the Nix manual in the
+     <link
+    xlink:href="http://hydra.nixos.org/job/nix/trunk/tarball/latest/download-by-type/doc/manual/#chap-writing-nix-expressions">chapter
+     on writing Nix expressions</link>.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Add a call to the function defined in the previous step to
+     <link
+    xlink:href="https://github.com/NixOS/nixpkgs/blob/master/pkgs/top-level/all-packages.nix"><filename>pkgs/top-level/all-packages.nix</filename></link>
+     with some descriptive name for the variable, e.g.
+     <varname>libfoo</varname>.
+<screen>
+$ emacs pkgs/top-level/all-packages.nix</screen>
+    </para>
+    <para>
+     The attributes in that file are sorted by category (like “Development /
+     Libraries”) that more-or-less correspond to the directory structure of
+     Nixpkgs, and then by attribute name.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     To test whether the package builds, run the following command from the
+     root of the nixpkgs source tree:
+<screen>
+$ nix-build -A libfoo</screen>
+     where <varname>libfoo</varname> should be the variable name defined in the
+     previous step. You may want to add the flag <option>-K</option> to keep
+     the temporary build directory in case something fails. If the build
+     succeeds, a symlink <filename>./result</filename> to the package in the
+     Nix store is created.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     If you want to install the package into your profile (optional), do
+<screen>
+$ nix-env -f . -iA libfoo</screen>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Optionally commit the new package and open a pull request, or send a patch
+     to <literal>https://groups.google.com/forum/#!forum/nix-devel</literal>.
+    </para>
+   </listitem>
+  </orderedlist>
+ </para>
+</chapter>
diff --git a/nixpkgs/doc/release-notes.xml b/nixpkgs/doc/release-notes.xml
new file mode 100644
index 000000000000..8d9b1813010a
--- /dev/null
+++ b/nixpkgs/doc/release-notes.xml
@@ -0,0 +1,800 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<article xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink">
+ <title>Nixpkgs Release Notes</title>
+ <section xml:id="release-notes-0.14">
+  <title>Release 0.14 (June 4, 2012)</title>
+
+  <para>
+   In preparation for the switch from Subversion to Git, this release is mainly
+   the prevent the Nixpkgs version number from going backwards. (This would
+   happen because prerelease version numbers produced for the Git repository
+   are lower than those for the Subversion repository.)
+  </para>
+
+  <para>
+   Since the last release, there have been thousands of changes and new
+   packages by numerous contributors. For details, see the commit logs.
+  </para>
+ </section>
+ <section xml:id="release-notes-0.13">
+  <title>Release 0.13 (February 5, 2010)</title>
+
+  <para>
+   As always, there are many changes. Some of the most important updates are:
+   <itemizedlist>
+    <listitem>
+     <para>
+      Glibc 2.9.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      GCC 4.3.3.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Linux 2.6.32.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      X.org 7.5.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      KDE 4.3.4.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+ </section>
+ <section xml:id="release-notes-0.12">
+  <title>Release 0.12 (April 24, 2009)</title>
+
+  <para>
+   There are way too many additions to Nixpkgs since the last release to list
+   here: for example, the number of packages on Linux has increased from 1002
+   to 2159. However, some specific improvements are worth listing:
+   <itemizedlist>
+    <listitem>
+     <para>
+      Nixpkgs now has a manual. In particular, it describes the standard build
+      environment in detail.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Major new packages:
+      <itemizedlist>
+       <listitem>
+        <para>
+         KDE 4.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         TeXLive.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         VirtualBox.
+        </para>
+       </listitem>
+      </itemizedlist>
+      … and many others.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Important updates:
+      <itemizedlist>
+       <listitem>
+        <para>
+         Glibc 2.7.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         GCC 4.2.4.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Linux 2.6.25 — 2.6.28.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Firefox 3.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         X.org 7.3.
+        </para>
+       </listitem>
+      </itemizedlist>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Support for building derivations in a virtual machine, including RPM and
+      Debian builds in automatically generated VM images. See
+      <filename>pkgs/build-support/vm/default.nix</filename> for details.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Improved support for building Haskell packages.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+
+  <para>
+   The following people contributed to this release: Andres Löh, Arie
+   Middelkoop, Armijn Hemel, Eelco Dolstra, Lluís Batlle, Ludovic Courtès,
+   Marc Weber, Mart Kolthof, Martin Bravenboer, Michael Raskin, Nicolas
+   Pierron, Peter Simons, Pjotr Prins, Rob Vermaas, Sander van der Burg, Tobias
+   Hammerschmidt, Valentin David, Wouter den Breejen and Yury G. Kudryashov. In
+   addition, several people contributed patches on the
+   <literal>nix-dev</literal> mailing list.
+  </para>
+ </section>
+ <section xml:id="release-notes-0.11">
+  <title>Release 0.11 (September 11, 2007)</title>
+
+  <para>
+   This release has the following improvements:
+   <itemizedlist>
+    <listitem>
+     <para>
+      The standard build environment (<literal>stdenv</literal>) is now pure on
+      the <literal>x86_64-linux</literal> and <literal>powerpc-linux</literal>
+      platforms, just as on <literal>i686-linux</literal>. (Purity means that
+      building and using the standard environment has no dependencies outside
+      of the Nix store. For instance, it doesn’t require an external C
+      compiler such as <filename>/usr/bin/gcc</filename>.) Also, the statically
+      linked binaries used in the bootstrap process are now automatically
+      reproducible, making it easy to update the bootstrap tools and to add
+      support for other Linux platforms. See
+      <filename>pkgs/stdenv/linux/make-bootstrap-tools.nix</filename> for
+      details.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Hook variables in the generic builder are now executed using the
+      <function>eval</function> shell command. This has a major advantage: you
+      can write hooks directly in Nix expressions. For instance, rather than
+      writing a builder like this:
+<programlisting>
+source $stdenv/setup
+
+postInstall=postInstall
+postInstall() {
+    ln -sf gzip $out/bin/gunzip
+    ln -sf gzip $out/bin/zcat
+}
+
+genericBuild</programlisting>
+      (the <literal>gzip</literal> builder), you can just add this attribute to
+      the derivation:
+<programlisting>
+postInstall = "ln -sf gzip $out/bin/gunzip; ln -sf gzip $out/bin/zcat";</programlisting>
+      and so a separate build script becomes unnecessary. This should allow us
+      to get rid of most builders in Nixpkgs.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      It is now possible to have the generic builder pass arguments to
+      <command>configure</command> and <command>make</command> that contain
+      whitespace. Previously, for example, you could say in a builder,
+<programlisting>
+configureFlags="CFLAGS=-O0"</programlisting>
+      but not
+<programlisting>
+configureFlags="CFLAGS=-O0 -g"</programlisting>
+      since the <literal>-g</literal> would be interpreted as a separate
+      argument to <command>configure</command>. Now you can say
+<programlisting>
+configureFlagsArray=("CFLAGS=-O0 -g")</programlisting>
+      or similarly
+<programlisting>
+configureFlagsArray=("CFLAGS=-O0 -g" "LDFLAGS=-L/foo -L/bar")</programlisting>
+      which does the right thing. Idem for <literal>makeFlags</literal>,
+      <literal>installFlags</literal>, <literal>checkFlags</literal> and
+      <literal>distFlags</literal>.
+     </para>
+     <para>
+      Unfortunately you can't pass arrays to Bash through the environment, so
+      you can't put the array above in a Nix expression, e.g.,
+<programlisting>
+configureFlagsArray = ["CFLAGS=-O0 -g"];</programlisting>
+      since it would just be flattened to a since string. However, you
+      <emphasis>can</emphasis> use the inline hooks described above:
+<programlisting>
+preConfigure = "configureFlagsArray=(\"CFLAGS=-O0 -g\")";</programlisting>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The function <function>fetchurl</function> now has support for two
+      different kinds of mirroring of files. First, it has support for
+      <emphasis>content-addressable mirrors</emphasis>. For example, given the
+      <function>fetchurl</function> call
+<programlisting>
+fetchurl {
+  url = http://releases.mozilla.org/<replaceable>...</replaceable>/firefox-2.0.0.6-source.tar.bz2;
+  sha1 = "eb72f55e4a8bf08e8c6ef227c0ade3d068ba1082";
+}</programlisting>
+      <function>fetchurl</function> will first try to download this file from
+      <link
+  xlink:href="http://tarballs.nixos.org/sha1/eb72f55e4a8bf08e8c6ef227c0ade3d068ba1082"/>.
+      If that file doesn’t exist, it will try the original URL. In general,
+      the “content-addressed” location is
+      <replaceable>mirror</replaceable><literal>/</literal><replaceable>hash-type</replaceable><literal>/</literal><replaceable>hash</replaceable>.
+      There is currently only one content-addressable mirror
+      (<link
+  xlink:href="http://tarballs.nixos.org"/>), but more can be
+      specified in the <varname>hashedMirrors</varname> attribute in
+      <filename>pkgs/build-support/fetchurl/mirrors.nix</filename>, or by
+      setting the <envar>NIX_HASHED_MIRRORS</envar> environment variable to a
+      whitespace-separated list of URLs.
+     </para>
+     <para>
+      Second, <function>fetchurl</function> has support for widely-mirrored
+      distribution sites such as SourceForge or the Linux kernel archives.
+      Given a URL of the form
+      <literal>mirror://<replaceable>site</replaceable>/<replaceable>path</replaceable></literal>,
+      it will try to download <replaceable>path</replaceable> from a
+      configurable list of mirrors for <replaceable>site</replaceable>. (This
+      idea was borrowed from Gentoo Linux.) Example:
+<programlisting>
+fetchurl {
+  url = mirror://gnu/gcc/gcc-4.2.0/gcc-core-4.2.0.tar.bz2;
+  sha256 = "0ykhzxhr8857dr97z0j9wyybfz1kjr71xk457cfapfw5fjas4ny1";
+}</programlisting>
+      Currently <replaceable>site</replaceable> can be
+      <literal>sourceforge</literal>, <literal>gnu</literal> and
+      <literal>kernel</literal>. The list of mirrors is defined in
+      <filename>pkgs/build-support/fetchurl/mirrors.nix</filename>. You can
+      override the list of mirrors for a particular site by setting the
+      environment variable
+      <envar>NIX_MIRRORS_<replaceable>site</replaceable></envar>, e.g.
+<programlisting>
+export NIX_MIRRORS_sourceforge=http://osdn.dl.sourceforge.net/sourceforge/</programlisting>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Important updates:
+      <itemizedlist>
+       <listitem>
+        <para>
+         Glibc 2.5.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         GCC 4.1.2.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Gnome 2.16.3.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         X11R7.2.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Linux 2.6.21.7 and 2.6.22.6.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Emacs 22.1.
+        </para>
+       </listitem>
+      </itemizedlist>
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Major new packages:
+      <itemizedlist>
+       <listitem>
+        <para>
+         KDE 3.5.6 Base.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Wine 0.9.43.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         OpenOffice 2.2.1.
+        </para>
+       </listitem>
+       <listitem>
+        <para>
+         Many Linux system packages to support NixOS.
+        </para>
+       </listitem>
+      </itemizedlist>
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+
+  <para>
+   The following people contributed to this release: Andres Löh, Arie
+   Middelkoop, Armijn Hemel, Eelco Dolstra, Marc Weber, Mart Kolthof, Martin
+   Bravenboer, Michael Raskin, Wouter den Breejen and Yury G. Kudryashov.
+  </para>
+ </section>
+ <section xml:id="release-notes-0.10">
+  <title>Release 0.10 (October 12, 2006)</title>
+
+  <note>
+   <para>
+    This release of Nixpkgs requires
+    <link
+xlink:href='http://nixos.org/releases/nix/nix-0.10/'>Nix 0.10</link>
+    or higher.
+   </para>
+  </note>
+
+  <para>
+   This release has the following improvements:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     <filename>pkgs/system/all-packages-generic.nix</filename> is gone, we now
+     just have <filename>pkgs/top-level/all-packages.nix</filename> that
+     contains all available packages. This should cause much less confusion
+     with users. <filename>all-packages.nix</filename> is a function that by
+     default returns packages for the current platform, but you can override
+     this by specifying a different <varname>system</varname> argument.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Certain packages in Nixpkgs are now user-configurable through a
+     configuration file, i.e., without having to edit the Nix expressions in
+     Nixpkgs. For instance, the Firefox provided in the Nixpkgs channel is
+     built without the RealPlayer plugin (for legal reasons). Previously, you
+     could easily enable RealPlayer support by editing the call to the Firefox
+     function in <filename>all-packages.nix</filename>, but such changes are
+     not respected when Firefox is subsequently updated through the Nixpkgs
+     channel.
+    </para>
+    <para>
+     The Nixpkgs configuration file (found in
+     <filename>~/.nixpkgs/config.nix</filename> or through the
+     <envar>NIXPKGS_CONFIG</envar> environment variable) is an attribute set
+     that contains configuration options that
+     <filename>all-packages.nix</filename> reads and uses for certain packages.
+     For instance, the following configuration file:
+<programlisting>
+{
+  firefox = {
+    enableRealPlayer = true;
+  };
+}</programlisting>
+     persistently enables RealPlayer support in the Firefox build.
+    </para>
+    <para>
+     (Actually, <literal>firefox.enableRealPlayer</literal> is the
+     <emphasis>only</emphasis> configuration option currently available, but
+     more are sure to be added.)
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Support for new platforms:
+     <itemizedlist>
+      <listitem>
+       <para>
+        <literal>i686-cygwin</literal>, i.e., Windows (using
+        <link xlink:href="http://www.cygwin.com/">Cygwin</link>). The standard
+        environment on <literal>i686-cygwin</literal> by default builds
+        binaries for the Cygwin environment (i.e., it uses Cygwin tools and
+        produces executables that use the Cygwin library). However, there is
+        also a standard environment that produces binaries that use
+        <link
+      xlink:href="http://www.mingw.org/">MinGW</link>. You can
+        use it by calling <filename>all-package.nix</filename> with the
+        <varname>stdenvType</varname> argument set to
+        <literal>"i686-mingw"</literal>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        <literal>i686-darwin</literal>, i.e., Mac OS X on Intel CPUs.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        <literal>powerpc-linux</literal>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        <literal>x86_64-linux</literal>, i.e., Linux on 64-bit AMD/Intel CPUs.
+        Unlike <literal>i686-linux</literal>, this platform doesn’t have a
+        pure <literal>stdenv</literal> yet.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     The default compiler is now GCC 4.1.1.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     X11 updated to X.org’s X11R7.1.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Notable new packages:
+     <itemizedlist>
+      <listitem>
+       <para>
+        Opera.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Microsoft Visual C++ 2005 Express Edition and the Windows SDK.
+       </para>
+      </listitem>
+     </itemizedlist>
+     In total there are now around 809 packages in Nixpkgs.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     It is now <emphasis>much</emphasis> easier to override the default C
+     compiler and other tools in <literal>stdenv</literal> for specific
+     packages. <filename>all-packages.nix</filename> provides two utility
+     functions for this purpose: <function>overrideGCC</function> and
+     <function>overrideInStdenv</function>. Both take a
+     <literal>stdenv</literal> and return an augmented
+     <literal>stdenv</literal>; the formed changes the C compiler, and the
+     latter adds additional packages to the front of
+     <literal>stdenv</literal>’s initial <envar>PATH</envar>, allowing tools
+     to be overridden.
+    </para>
+    <para>
+     For instance, the package <varname>strategoxt</varname> doesn’t build
+     with the GNU Make in <literal>stdenv</literal> (version 3.81), so we call
+     it with an augmented <literal>stdenv</literal> that uses GNU Make 3.80:
+<programlisting>
+strategoxt = (import ../development/compilers/strategoxt) {
+  inherit fetchurl pkgconfig sdf aterm;
+  stdenv = overrideInStdenv stdenv [gnumake380];
+};
+
+gnumake380 = <replaceable>...</replaceable>;</programlisting>
+     Likewise, there are many packages that don’t compile with the default
+     GCC (4.1.1), but that’s easily fixed:
+<programlisting>
+exult = import ../games/exult {
+  inherit fetchurl SDL SDL_mixer zlib libpng unzip;
+  stdenv = overrideGCC stdenv gcc34;
+};</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     It has also become much easier to experiment with changes to the
+     <literal>stdenv</literal> setup script (which notably contains the generic
+     builder). Since edits to <filename>pkgs/stdenv/generic/setup.sh</filename>
+     trigger a rebuild of <emphasis>everything</emphasis>, this was formerly
+     quite painful. But now <literal>stdenv</literal> contains a function to
+     “regenerate” <literal>stdenv</literal> with a different setup script,
+     allowing the use of a different setup script for specific packages:
+<programlisting>
+pkg = import <replaceable>...</replaceable> {
+  stdenv = stdenv.regenerate ./my-setup.sh;
+  <replaceable>...</replaceable>
+}</programlisting>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Packages can now have a human-readable <emphasis>description</emphasis>
+     field. Package descriptions are shown by <literal>nix-env -qa
+     --description</literal>. In addition, they’re shown on the Nixpkgs
+     release page. A description can be added to a package as follows:
+<programlisting>
+stdenv.mkDerivation {
+  name = "exult-1.2";
+  <replaceable>...</replaceable>
+  meta = {
+    description = "A reimplementation of the Ultima VII game engine";
+  };
+}</programlisting>
+     The <varname>meta</varname> attribute is not passed to the builder, so
+     changes to the description do not trigger a rebuild. Additional
+     <varname>meta</varname> attributes may be defined in the future (such as
+     the URL of the package’s homepage, the license, etc.).
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <para>
+   The following people contributed to this release: Andres Löh, Armijn Hemel,
+   Christof Douma, Eelco Dolstra, Eelco Visser, Mart Kolthof, Martin
+   Bravenboer, Merijn de Jonge, Rob Vermaas and Roy van den Broek.
+  </para>
+ </section>
+ <section xml:id="release-notes-0.9">
+  <title>Release 0.9 (January 31, 2006)</title>
+
+  <para>
+   There have been zillions of changes since the last release of Nixpkgs. Many
+   packages have been added or updated. The following are some of the more
+   notable changes:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Distribution files have been moved to
+     <link
+  xlink:href="http://nixos.org/" />.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     The C library on Linux, Glibc, has been updated to version 2.3.6.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     The default compiler is now GCC 3.4.5. GCC 4.0.2 is also available.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     The old, unofficial Xlibs has been replaced by the official modularised
+     X11 distribution from X.org, i.e., X11R7.0. X11R7.0 consists of 287 (!)
+     packages, all of which are in Nixpkgs though not all have been tested. It
+     is now possible to build a working X server (previously we only had X
+     client libraries). We use a fully Nixified X server on NixOS.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     The Sun JDK 5 has been purified, i.e., it doesn’t require any non-Nix
+     components such as <filename>/lib/ld-linux.so.2</filename>. This means
+     that Java applications such as Eclipse and Azureus can run on NixOS.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Hardware-accelerated OpenGL support, used by games like Quake 3 (which is
+     now built from source).
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Improved support for FreeBSD on x86.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Improved Haskell support; e.g., the GHC build is now pure.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Some support for cross-compilation: cross-compiling builds of GCC and
+     Binutils, and cross-compiled builds of the C library uClibc.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Notable new packages:
+     <itemizedlist>
+      <listitem>
+       <para>
+        teTeX, including support for building LaTeX documents using Nix (with
+        automatic dependency determination).
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Ruby.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        System-level packages to support NixOS, e.g. Grub, GNU
+        <literal>parted</literal> and so on.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        <literal>ecj</literal>, the Eclipse Compiler for Java, so we finally
+        have a freely distributable compiler that supports Java 5.0.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        <literal>php</literal>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        The GIMP.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Inkscape.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        GAIM.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        <literal>kdelibs</literal>. This allows us to add KDE-based packages
+        (such as <literal>kcachegrind</literal>).
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <para>
+   The following people contributed to this release: Andres Löh, Armijn Hemel,
+   Bogdan Dumitriu, Christof Douma, Eelco Dolstra, Eelco Visser, Mart Kolthof,
+   Martin Bravenboer, Rob Vermaas and Roy van den Broek.
+  </para>
+ </section>
+ <section xml:id="release-notes-0.8">
+  <title>Release 0.8 (April 11, 2005)</title>
+
+  <para>
+   This release is mostly to remain synchronised with the changed hashing
+   scheme in Nix 0.8.
+  </para>
+
+  <para>
+   Notable updates:
+   <itemizedlist>
+    <listitem>
+     <para>
+      Adobe Reader 7.0
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Various security updates (zlib 1.2.2, etc.)
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+ </section>
+ <section xml:id="release-notes-0.7">
+  <title>Release 0.7 (March 14, 2005)</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     The bootstrap process for the standard build environment on Linux
+     (stdenv-linux) has been improved. It is no longer dependent in its initial
+     bootstrap stages on the system Glibc, GCC, and other tools. Rather,
+     Nixpkgs contains a statically linked bash and curl, and uses that to
+     download other statically linked tools. These are then used to build a
+     Glibc and dynamically linked versions of all other tools.
+    </para>
+    <para>
+     This change also makes the bootstrap process faster. For instance, GCC is
+     built only once instead of three times.
+    </para>
+    <para>
+     (Contributed by Armijn Hemel.)
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Tarballs used by Nixpkgs are now obtained from the same server that hosts
+     Nixpkgs (<link
+  xlink:href="http://catamaran.labs.cs.uu.nl/" />). This
+     reduces the risk of packages being unbuildable due to moved or deleted
+     files on various servers.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     There now is a generic mechanism for building Perl modules. See the
+     various Perl modules defined in pkgs/system/all-packages-generic.nix.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Notable new packages:
+     <itemizedlist>
+      <listitem>
+       <para>
+        Qt 3
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        MySQL
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        MythTV
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Mono
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        MonoDevelop (alpha)
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Xine
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Notable updates:
+     <itemizedlist>
+      <listitem>
+       <para>
+        GCC 3.4.3
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Glibc 2.3.4
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        GTK 2.6
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+</article>
diff --git a/nixpkgs/doc/reviewing-contributions.xml b/nixpkgs/doc/reviewing-contributions.xml
new file mode 100644
index 000000000000..5618567e3852
--- /dev/null
+++ b/nixpkgs/doc/reviewing-contributions.xml
@@ -0,0 +1,616 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+        xmlns:xlink="http://www.w3.org/1999/xlink"
+        xmlns:xi="http://www.w3.org/2001/XInclude"
+        version="5.0"
+        xml:id="sec-reviewing-contributions">
+ <title>Reviewing contributions</title>
+ <warning>
+  <para>
+   The following section is a draft, and the policy for reviewing is still
+   being discussed in issues such as
+   <link
+	   xlink:href="https://github.com/NixOS/nixpkgs/issues/11166">#11166
+   </link> and
+   <link
+	   xlink:href="https://github.com/NixOS/nixpkgs/issues/20836">#20836
+   </link>.
+  </para>
+ </warning>
+ <para>
+  The Nixpkgs project receives a fairly high number of contributions via GitHub
+  pull requests. Reviewing and approving these is an important task and a way
+  to contribute to the project.
+ </para>
+ <para>
+  The high change rate of Nixpkgs makes any pull request that remains open for
+  too long subject to conflicts that will require extra work from the submitter
+  or the merger. Reviewing pull requests in a timely manner and being responsive
+  to the comments is the key to avoid this issue. GitHub provides sort filters
+  that can be used to see the <link
+  xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-desc">most
+  recently</link> and the <link
+  xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+sort%3Aupdated-asc">least
+  recently</link> updated pull requests. We highly encourage looking at
+  <link xlink:href="https://github.com/NixOS/nixpkgs/pulls?q=is%3Apr+is%3Aopen+review%3Anone+status%3Asuccess+-label%3A%222.status%3A+work-in-progress%22+no%3Aproject+no%3Aassignee+no%3Amilestone">
+  this list of ready to merge, unreviewed pull requests</link>.
+ </para>
+ <para>
+  When reviewing a pull request, please always be nice and polite.
+  Controversial changes can lead to controversial opinions, but it is important
+  to respect every community member and their work.
+ </para>
+ <para>
+  GitHub provides reactions as a simple and quick way to provide feedback to
+  pull requests or any comments. The thumb-down reaction should be used with
+  care and if possible accompanied with some explanation so the submitter has
+  directions to improve their contribution.
+ </para>
+ <para>
+  pull request reviews should include a list of what has been reviewed in a
+  comment, so other reviewers and mergers can know the state of the review.
+ </para>
+ <para>
+  All the review template samples provided in this section are generic and
+  meant as examples. Their usage is optional and the reviewer is free to adapt
+  them to their liking.
+ </para>
+ <section xml:id="reviewing-contributions-package-updates">
+  <title>Package updates</title>
+
+  <para>
+   A package update is the most trivial and common type of pull request. These
+   pull requests mainly consist of updating the version part of the package
+   name and the source hash.
+  </para>
+
+  <para>
+   It can happen that non-trivial updates include patches or more complex
+   changes.
+  </para>
+
+  <para>
+   Reviewing process:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Add labels to the pull request. (Requires commit rights)
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>8.has: package (update)</literal> and any topic label that fit
+       the updated package.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the package versioning fits the guidelines.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the commit text fits the guidelines.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the package maintainers are notified.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <link xlink:href="https://help.github.com/articles/about-codeowners/">CODEOWNERS</link>
+       will make GitHub notify users based on the submitted changes, but it can
+       happen that it misses some of the package maintainers.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the meta field information is correct.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       License can change with version updates, so it should be checked to
+       match the upstream license.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       If the package has no maintainer, a maintainer must be set. This can be
+       the update submitter or a community member that accepts to take
+       maintainership of the package.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the code contains no typos.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Building the package locally.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       pull requests are often targeted to the master or staging branch, and
+       building the pull request locally when it is submitted can trigger many
+       source builds.
+      </para>
+      <para>
+       It is possible to rebase the changes on nixos-unstable or
+       nixpkgs-unstable for easier review by running the following commands
+       from a nixpkgs clone.
+<screen>
+$ git remote add channels https://github.com/NixOS/nixpkgs-channels.git <co
+  xml:id='reviewing-rebase-1' />
+$ git fetch channels nixos-unstable <co xml:id='reviewing-rebase-2' />
+$ git fetch origin pull/PRNUMBER/head <co xml:id='reviewing-rebase-3' />
+$ git rebase --onto nixos-unstable BASEBRANCH FETCH_HEAD <co
+  xml:id='reviewing-rebase-4' />
+</screen>
+       <calloutlist>
+        <callout arearefs='reviewing-rebase-1'>
+         <para>
+          This should be done only once to be able to fetch channel branches
+          from the nixpkgs-channels repository.
+         </para>
+        </callout>
+        <callout arearefs='reviewing-rebase-2'>
+         <para>
+          Fetching the nixos-unstable branch.
+         </para>
+        </callout>
+        <callout arearefs='reviewing-rebase-3'>
+         <para>
+          Fetching the pull request changes, <varname>PRNUMBER</varname> is the
+          number at the end of the pull request title and
+          <varname>BASEBRANCH</varname> the base branch of the pull request.
+         </para>
+        </callout>
+        <callout arearefs='reviewing-rebase-4'>
+         <para>
+          Rebasing the pull request changes to the nixos-unstable branch.
+         </para>
+        </callout>
+       </calloutlist>
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       The <link xlink:href="https://github.com/madjar/nox">nox</link> tool can
+       be used to review a pull request content in a single command. It doesn't
+       rebase on a channel branch so it might trigger multiple source builds.
+       <varname>PRNUMBER</varname> should be replaced by the number at the end
+       of the pull request title.
+      </para>
+<screen>
+$ nix-shell -p nox --run "nox-review -k pr PRNUMBER"
+</screen>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Running every binary.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <example xml:id="reviewing-contributions-sample-package-update">
+   <title>Sample template for a package update review</title>
+<screen>
+##### Reviewed points
+
+- [ ] package name fits guidelines
+- [ ] package version fits guidelines
+- [ ] package build on ARCHITECTURE
+- [ ] executables tested on ARCHITECTURE
+- [ ] all depending packages build
+
+##### Possible improvements
+
+##### Comments
+
+</screen>
+  </example>
+ </section>
+ <section xml:id="reviewing-contributions-new-packages">
+  <title>New packages</title>
+
+  <para>
+   New packages are a common type of pull requests. These pull requests
+   consists in adding a new nix-expression for a package.
+  </para>
+
+  <para>
+   Reviewing process:
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Add labels to the pull request. (Requires commit rights)
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>8.has: package (new)</literal> and any topic label that fit the
+       new package.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the package versioning is fitting the guidelines.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the commit name is fitting the guidelines.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the meta field contains correct information.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       License must be checked to be fitting upstream license.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       Platforms should be set or the package will not get binary substitutes.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       A maintainer must be set. This can be the package submitter or a
+       community member that accepts to take maintainership of the package.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the code contains no typos.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure the package source.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       Mirrors urls should be used when available.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       The most appropriate function should be used (e.g. packages from GitHub
+       should use <literal>fetchFromGitHub</literal>).
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Building the package locally.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Running every binary.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <example xml:id="reviewing-contributions-sample-new-package">
+   <title>Sample template for a new package review</title>
+<screen>
+##### Reviewed points
+
+- [ ] package path fits guidelines
+- [ ] package name fits guidelines
+- [ ] package version fits guidelines
+- [ ] package build on ARCHITECTURE
+- [ ] executables tested on ARCHITECTURE
+- [ ] `meta.description` is set and fits guidelines
+- [ ] `meta.license` fits upstream license
+- [ ] `meta.platforms` is set
+- [ ] `meta.maintainers` is set
+- [ ] build time only dependencies are declared in `nativeBuildInputs`
+- [ ] source is fetched using the appropriate function
+- [ ] phases are respected
+- [ ] patches that are remotely available are fetched with `fetchpatch`
+
+##### Possible improvements
+
+##### Comments
+
+</screen>
+  </example>
+ </section>
+ <section xml:id="reviewing-contributions-module-updates">
+  <title>Module updates</title>
+
+  <para>
+   Module updates are submissions changing modules in some ways. These often
+   contains changes to the options or introduce new options.
+  </para>
+
+  <para>
+   Reviewing process
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Add labels to the pull request. (Requires commit rights)
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>8.has: module (update)</literal> and any topic label that fit
+       the module.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the module maintainers are notified.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <link xlink:href="https://help.github.com/articles/about-codeowners/">CODEOWNERS</link>
+       will make GitHub notify users based on the submitted changes, but it can
+       happen that it misses some of the package maintainers.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the module tests, if any, are succeeding.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the introduced options are correct.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       Type should be appropriate (string related types differs in their
+       merging capabilities, <literal>optionSet</literal> and
+       <literal>string</literal> types are deprecated).
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       Description, default and example should be provided.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that option changes are backward compatible.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>mkRenamedOptionModule</literal> and
+       <literal>mkAliasOptionModule</literal> functions provide way to make
+       option changes backward compatible.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that removed options are declared with
+     <literal>mkRemovedOptionModule</literal>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that changes that are not backward compatible are mentioned in
+     release notes.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that documentations affected by the change is updated.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <example xml:id="reviewing-contributions-sample-module-update">
+   <title>Sample template for a module update review</title>
+<screen>
+##### Reviewed points
+
+- [ ] changes are backward compatible
+- [ ] removed options are declared with `mkRemovedOptionModule`
+- [ ] changes that are not backward compatible are documented in release notes
+- [ ] module tests succeed on ARCHITECTURE
+- [ ] options types are appropriate
+- [ ] options description is set
+- [ ] options example is provided
+- [ ] documentation affected by the changes is updated
+
+##### Possible improvements
+
+##### Comments
+
+</screen>
+  </example>
+ </section>
+ <section xml:id="reviewing-contributions-new-modules">
+  <title>New modules</title>
+
+  <para>
+   New modules submissions introduce a new module to NixOS.
+  </para>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Add labels to the pull request. (Requires commit rights)
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       <literal>8.has: module (new)</literal> and any topic label that fit the
+       module.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the module tests, if any, are succeeding.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the introduced options are correct.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       Type should be appropriate (string related types differs in their
+       merging capabilities, <literal>optionSet</literal> and
+       <literal>string</literal> types are deprecated).
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       Description, default and example should be provided.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that module <literal>meta</literal> field is present
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       Maintainers should be declared in <literal>meta.maintainers</literal>.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       Module documentation should be declared with
+       <literal>meta.doc</literal>.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Ensure that the module respect other modules functionality.
+    </para>
+    <itemizedlist>
+     <listitem>
+      <para>
+       For example, enabling a module should not open firewall ports by
+       default.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+  </itemizedlist>
+
+  <example xml:id="reviewing-contributions-sample-new-module">
+   <title>Sample template for a new module review</title>
+<screen>
+##### Reviewed points
+
+- [ ] module path fits the guidelines
+- [ ] module tests succeed on ARCHITECTURE
+- [ ] options have appropriate types
+- [ ] options have default
+- [ ] options have example
+- [ ] options have descriptions
+- [ ] No unneeded package is added to environment.systemPackages
+- [ ] meta.maintainers is set
+- [ ] module documentation is declared in meta.doc
+
+##### Possible improvements
+
+##### Comments
+
+</screen>
+  </example>
+ </section>
+ <section xml:id="reviewing-contributions-other-submissions">
+  <title>Other submissions</title>
+
+  <para>
+   Other type of submissions requires different reviewing steps.
+  </para>
+
+  <para>
+   If you consider having enough knowledge and experience in a topic and would
+   like to be a long-term reviewer for related submissions, please contact the
+   current reviewers for that topic. They will give you information about the
+   reviewing process. The main reviewers for a topic can be hard to find as
+   there is no list, but checking past pull requests to see who reviewed or
+   git-blaming the code to see who committed to that topic can give some hints.
+  </para>
+
+  <para>
+   Container system, boot system and library changes are some examples of the
+   pull requests fitting this category.
+  </para>
+ </section>
+ <section xml:id="reviewing-contributions--merging-pull-requests">
+  <title>Merging pull requests</title>
+
+  <para>
+   It is possible for community members that have enough knowledge and
+   experience on a special topic to contribute by merging pull requests.
+  </para>
+
+  <para>
+   TODO: add the procedure to request merging rights.
+  </para>
+
+<!--
+The following paragraph about how to deal with unactive contributors is just a
+proposition and should be modified to what the community agrees to be the right
+policy.
+
+<para>Please note that contributors with commit rights unactive for more than
+  three months will have their commit rights revoked.</para>
+-->
+
+  <para>
+   In a case a contributor leaves definitively the Nix community, he should
+   create an issue or post on
+   <link
+   xlink:href="https://discourse.nixos.org">Discourse</link> with
+   references of packages and modules he maintains so the maintainership can be
+   taken over by other contributors.
+  </para>
+ </section>
+</chapter>
diff --git a/nixpkgs/doc/shell.nix b/nixpkgs/doc/shell.nix
new file mode 100644
index 000000000000..8ac2019f9d66
--- /dev/null
+++ b/nixpkgs/doc/shell.nix
@@ -0,0 +1,5 @@
+{ pkgs ? import ../. {} }:
+(import ./default.nix {}).overrideAttrs (x: {
+  buildInputs = x.buildInputs ++ [ pkgs.xmloscopy pkgs.ruby ];
+
+})
diff --git a/nixpkgs/doc/stdenv.xml b/nixpkgs/doc/stdenv.xml
new file mode 100644
index 000000000000..1c18fab86696
--- /dev/null
+++ b/nixpkgs/doc/stdenv.xml
@@ -0,0 +1,2905 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-stdenv">
+ <title>The Standard Environment</title>
+ <para>
+  The standard build environment in the Nix Packages collection provides an
+  environment for building Unix packages that does a lot of common build tasks
+  automatically. In fact, for Unix packages that use the standard
+  <literal>./configure; make; make install</literal> build interface, you
+  don’t need to write a build script at all; the standard environment does
+  everything automatically. If <literal>stdenv</literal> doesn’t do what you
+  need automatically, you can easily customise or override the various build
+  phases.
+ </para>
+ <section xml:id="sec-using-stdenv">
+  <title>Using <literal>stdenv</literal></title>
+
+  <para>
+   To build a package with the standard environment, you use the function
+   <varname>stdenv.mkDerivation</varname>, instead of the primitive built-in
+   function <varname>derivation</varname>, e.g.
+<programlisting>
+stdenv.mkDerivation {
+  name = "libfoo-1.2.3";
+  src = fetchurl {
+    url = http://example.org/libfoo-1.2.3.tar.bz2;
+    sha256 = "0x2g1jqygyr5wiwg4ma1nd7w4ydpy82z9gkcv8vh2v8dn3y58v5m";
+  };
+}</programlisting>
+   (<varname>stdenv</varname> needs to be in scope, so if you write this in a
+   separate Nix expression from <filename>pkgs/all-packages.nix</filename>, you
+   need to pass it as a function argument.) Specifying a
+   <varname>name</varname> and a <varname>src</varname> is the absolute minimum
+   you need to do. Many packages have dependencies that are not provided in the
+   standard environment. It’s usually sufficient to specify those
+   dependencies in the <varname>buildInputs</varname> attribute:
+<programlisting>
+stdenv.mkDerivation {
+  name = "libfoo-1.2.3";
+  ...
+  buildInputs = [libbar perl ncurses];
+}</programlisting>
+   This attribute ensures that the <filename>bin</filename> subdirectories of
+   these packages appear in the <envar>PATH</envar> environment variable during
+   the build, that their <filename>include</filename> subdirectories are
+   searched by the C compiler, and so on. (See
+   <xref linkend="ssec-setup-hooks"/> for details.)
+  </para>
+
+  <para>
+   Often it is necessary to override or modify some aspect of the build. To
+   make this easier, the standard environment breaks the package build into a
+   number of <emphasis>phases</emphasis>, all of which can be overridden or
+   modified individually: unpacking the sources, applying patches, configuring,
+   building, and installing. (There are some others; see
+   <xref linkend="sec-stdenv-phases"/>.) For instance, a package that doesn’t
+   supply a makefile but instead has to be compiled “manually” could be
+   handled like this:
+<programlisting>
+stdenv.mkDerivation {
+  name = "fnord-4.5";
+  ...
+  buildPhase = ''
+    gcc foo.c -o foo
+  '';
+  installPhase = ''
+    mkdir -p $out/bin
+    cp foo $out/bin
+  '';
+}</programlisting>
+   (Note the use of <literal>''</literal>-style string literals, which are very
+   convenient for large multi-line script fragments because they don’t need
+   escaping of <literal>"</literal> and <literal>\</literal>, and because
+   indentation is intelligently removed.)
+  </para>
+
+  <para>
+   There are many other attributes to customise the build. These are listed in
+   <xref linkend="ssec-stdenv-attributes"/>.
+  </para>
+
+  <para>
+   While the standard environment provides a generic builder, you can still
+   supply your own build script:
+<programlisting>
+stdenv.mkDerivation {
+  name = "libfoo-1.2.3";
+  ...
+  builder = ./builder.sh;
+}</programlisting>
+   where the builder can do anything it wants, but typically starts with
+<programlisting>
+source $stdenv/setup
+</programlisting>
+   to let <literal>stdenv</literal> set up the environment (e.g., process the
+   <varname>buildInputs</varname>). If you want, you can still use
+   <literal>stdenv</literal>’s generic builder:
+<programlisting>
+source $stdenv/setup
+
+buildPhase() {
+  echo "... this is my custom build phase ..."
+  gcc foo.c -o foo
+}
+
+installPhase() {
+  mkdir -p $out/bin
+  cp foo $out/bin
+}
+
+genericBuild
+</programlisting>
+  </para>
+ </section>
+ <section xml:id="sec-tools-of-stdenv">
+  <title>Tools provided by <literal>stdenv</literal></title>
+
+  <para>
+   The standard environment provides the following packages:
+   <itemizedlist>
+    <listitem>
+     <para>
+      The GNU C Compiler, configured with C and C++ support.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      GNU coreutils (contains a few dozen standard Unix commands).
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      GNU findutils (contains <command>find</command>).
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      GNU diffutils (contains <command>diff</command>, <command>cmp</command>).
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      GNU <command>sed</command>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      GNU <command>grep</command>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      GNU <command>awk</command>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      GNU <command>tar</command>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      <command>gzip</command>, <command>bzip2</command> and
+      <command>xz</command>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      GNU Make. It has been patched to provide <quote>nested</quote> output
+      that can be fed into the <command>nix-log2xml</command> command and
+      <command>log2html</command> stylesheet to create a structured, readable
+      output of the build steps performed by Make.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      Bash. This is the shell used for all builders in the Nix Packages
+      collection. Not using <command>/bin/sh</command> removes a large source
+      of portability problems.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      The <command>patch</command> command.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </para>
+
+  <para>
+   On Linux, <literal>stdenv</literal> also includes the
+   <command>patchelf</command> utility.
+  </para>
+ </section>
+ <section xml:id="ssec-stdenv-dependencies">
+  <title>Specifying dependencies</title>
+
+  <para>
+   As described in the Nix manual, almost any <filename>*.drv</filename> store
+   path in a derivation's attribute set will induce a dependency on that
+   derivation. <varname>mkDerivation</varname>, however, takes a few attributes
+   intended to, between them, include all the dependencies of a package. This
+   is done both for structure and consistency, but also so that certain other
+   setup can take place. For example, certain dependencies need their bin
+   directories added to the <envar>PATH</envar>. That is built-in, but other
+   setup is done via a pluggable mechanism that works in conjunction with these
+   dependency attributes. See <xref linkend="ssec-setup-hooks"/> for details.
+  </para>
+
+  <para>
+   Dependencies can be broken down along three axes: their host and target
+   platforms relative to the new derivation's, and whether they are propagated.
+   The platform distinctions are motivated by cross compilation; see
+   <xref linkend="chap-cross"/> for exactly what each platform means.
+   <footnote xml:id="footnote-stdenv-ignored-build-platform">
+    <para>
+     The build platform is ignored because it is a mere implementation detail
+     of the package satisfying the dependency: As a general programming
+     principle, dependencies are always <emphasis>specified</emphasis> as
+     interfaces, not concrete implementation.
+    </para>
+   </footnote>
+   But even if one is not cross compiling, the platforms imply whether or not
+   the dependency is needed at run-time or build-time, a concept that makes
+   perfect sense outside of cross compilation. For now, the run-time/build-time
+   distinction is just a hint for mental clarity, but in the future it perhaps
+   could be enforced.
+  </para>
+
+  <para>
+   The extension of <envar>PATH</envar> with dependencies, alluded to
+   above, proceeds according to the relative platforms alone. The
+   process is carried out only for dependencies whose host platform
+   matches the new derivation's build platform i.e. dependencies which
+   run on the platform where the new derivation will be built.
+   <footnote xml:id="footnote-stdenv-native-dependencies-in-path">
+    <para>
+     Currently, this means for native builds all dependencies are put
+     on the <envar>PATH</envar>. But in the future that may not be the
+     case for sake of matching cross: the platforms would be assumed
+     to be unique for native and cross builds alike, so only the
+     <varname>depsBuild*</varname> and
+     <varname>nativeBuildInputs</varname> would be added to the
+     <envar>PATH</envar>.
+    </para>
+   </footnote>
+   For each dependency <replaceable>dep</replaceable> of those dependencies,
+   <filename><replaceable>dep</replaceable>/bin</filename>, if present, is
+   added to the <envar>PATH</envar> environment variable.
+  </para>
+
+  <para>
+   The dependency is propagated when it forces some of its other-transitive
+   (non-immediate) downstream dependencies to also take it on as an immediate
+   dependency. Nix itself already takes a package's transitive dependencies into
+   account, but this propagation ensures nixpkgs-specific infrastructure like
+   setup hooks (mentioned above) also are run as if the propagated dependency.
+  </para>
+
+  <para>
+   It is important to note that dependencies are not necessarily propagated as
+   the same sort of dependency that they were before, but rather as the
+   corresponding sort so that the platform rules still line up. The exact rules
+   for dependency propagation can be given by assigning to each dependency two
+   integers based one how its host and target platforms are offset from the
+   depending derivation's platforms. Those offsets are given below in the
+   descriptions of each dependency list attribute. Algorithmically, we traverse
+   propagated inputs, accumulating every propagated dependency's propagated
+   dependencies and adjusting them to account for the "shift in perspective"
+   described by the current dependency's platform offsets. This results in sort
+   a transitive closure of the dependency relation, with the offsets being
+   approximately summed when two dependency links are combined. We also prune
+   transitive dependencies whose combined offsets go out-of-bounds, which can be
+   viewed as a filter over that transitive closure removing dependencies that
+   are blatantly absurd.
+  </para>
+
+  <para>
+   We can define the process precisely with
+   <link xlink:href="https://en.wikipedia.org/wiki/Natural_deduction">Natural
+   Deduction</link> using the inference rules. This probably seems a bit
+   obtuse, but so is the bash code that actually implements it!
+   <footnote xml:id="footnote-stdenv-find-inputs-location">
+    <para>
+     The <function>findInputs</function> function, currently residing in
+     <filename>pkgs/stdenv/generic/setup.sh</filename>, implements the
+     propagation logic.
+    </para>
+   </footnote>
+   They're confusing in very different ways so... hopefully if something doesn't
+   make sense in one presentation, it will in the other!
+<programlisting>
+let mapOffset(h, t, i) = i + (if i &lt;= 0 then h else t - 1)
+
+propagated-dep(h0, t0, A, B)
+propagated-dep(h1, t1, B, C)
+h0 + h1 in {-1, 0, 1}
+h0 + t1 in {-1, 0, 1}
+-------------------------------------- Transitive property
+propagated-dep(mapOffset(h0, t0, h1),
+               mapOffset(h0, t0, t1),
+               A, C)</programlisting>
+<programlisting>
+let mapOffset(h, t, i) = i + (if i &lt;= 0 then h else t - 1)
+
+dep(h0, _, A, B)
+propagated-dep(h1, t1, B, C)
+h0 + h1 in {-1, 0, 1}
+h0 + t1 in {-1, 0, -1}
+----------------------------- Take immediate dependencies' propagated dependencies
+propagated-dep(mapOffset(h0, t0, h1),
+               mapOffset(h0, t0, t1),
+               A, C)</programlisting>
+<programlisting>
+propagated-dep(h, t, A, B)
+----------------------------- Propagated dependencies count as dependencies
+dep(h, t, A, B)</programlisting>
+   Some explanation of this monstrosity is in order. In the common case, the
+   target offset of a dependency is the successor to the target offset:
+   <literal>t = h + 1</literal>. That means that:
+<programlisting>
+let f(h, t, i) = i + (if i &lt;= 0 then h else t - 1)
+let f(h, h + 1, i) = i + (if i &lt;= 0 then h else (h + 1) - 1)
+let f(h, h + 1, i) = i + (if i &lt;= 0 then h else h)
+let f(h, h + 1, i) = i + h
+  </programlisting>
+   This is where "sum-like" comes in from above: We can just sum all of the host
+   offsets to get the host offset of the transitive dependency. The target
+   offset is the transitive dependency is simply the host offset + 1, just as it
+   was with the dependencies composed to make this transitive one; it can be
+   ignored as it doesn't add any new information.
+  </para>
+
+  <para>
+   Because of the bounds checks, the uncommon cases are <literal>h = t</literal>
+   and <literal>h + 2 = t</literal>. In the former case, the motivation for
+   <function>mapOffset</function> is that since its host and target platforms
+   are the same, no transitive dependency of it should be able to "discover" an
+   offset greater than its reduced target offsets.
+   <function>mapOffset</function> effectively "squashes" all its transitive
+   dependencies' offsets so that none will ever be greater than the target
+   offset of the original <literal>h = t</literal> package. In the other case,
+   <literal>h + 1</literal> is skipped over between the host and target offsets.
+   Instead of squashing the offsets, we need to "rip" them apart so no
+   transitive dependencies' offset is that one.
+  </para>
+
+  <para>
+   Overall, the unifying theme here is that propagation shouldn't be introducing
+   transitive dependencies involving platforms the depending package is unaware
+   of. The offset bounds checking and definition of
+   <function>mapOffset</function> together ensure that this is the case.
+   Discovering a new offset is discovering a new platform, and since those
+   platforms weren't in the derivation "spec" of the needing package, they
+   cannot be relevant. From a capability perspective, we can imagine that the
+   host and target platforms of a package are the capabilities a package
+   requires, and the depending package must provide the capability to the
+   dependency.
+  </para>
+
+  <variablelist>
+   <title>Variables specifying dependencies</title>
+   <varlistentry>
+    <term>
+     <varname>depsBuildBuild</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of dependencies whose host and target platforms are the new
+      derivation's build platform. This means a <literal>-1</literal> host and
+      <literal>-1</literal> target offset from the new derivation's platforms.
+      These are programs and libraries used at build time that produce programs
+      and libraries also used at build time. If the dependency doesn't care
+      about the target platform (i.e. isn't a compiler or similar tool), put it
+      in <varname>nativeBuildInputs</varname> instead. The most common use of
+      this <literal>buildPackages.stdenv.cc</literal>, the default C compiler
+      for this role. That example crops up more than one might think in old
+      commonly used C libraries.
+     </para>
+     <para>
+      Since these packages are able to be run at build-time, they are always
+      added to the <envar>PATH</envar>, as described above. But since these
+      packages are only guaranteed to be able to run then, they shouldn't
+      persist as run-time dependencies. This isn't currently enforced, but could
+      be in the future.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>nativeBuildInputs</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of dependencies whose host platform is the new derivation's build
+      platform, and target platform is the new derivation's host platform. This
+      means a <literal>-1</literal> host offset and <literal>0</literal> target
+      offset from the new derivation's platforms. These are programs and
+      libraries used at build-time that, if they are a compiler or similar tool,
+      produce code to run at run-time—i.e. tools used to build the new
+      derivation. If the dependency doesn't care about the target platform (i.e.
+      isn't a compiler or similar tool), put it here, rather than in
+      <varname>depsBuildBuild</varname> or <varname>depsBuildTarget</varname>.
+      This could be called <varname>depsBuildHost</varname> but
+      <varname>nativeBuildInputs</varname> is used for historical continuity.
+     </para>
+     <para>
+      Since these packages are able to be run at build-time, they are added to
+      the <envar>PATH</envar>, as described above. But since these packages are
+      only guaranteed to be able to run then, they shouldn't persist as run-time
+      dependencies. This isn't currently enforced, but could be in the future.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>depsBuildTarget</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of dependencies whose host platform is the new derivation's build
+      platform, and target platform is the new derivation's target platform.
+      This means a <literal>-1</literal> host offset and <literal>1</literal>
+      target offset from the new derivation's platforms. These are programs used
+      at build time that produce code to run with code produced by the depending
+      package. Most commonly, these are tools used to build the runtime or
+      standard library that the currently-being-built compiler will inject into
+      any code it compiles. In many cases, the currently-being-built-compiler is
+      itself employed for that task, but when that compiler won't run (i.e. its
+      build and host platform differ) this is not possible. Other times, the
+      compiler relies on some other tool, like binutils, that is always built
+      separately so that the dependency is unconditional.
+     </para>
+     <para>
+      This is a somewhat confusing concept to wrap one’s head around, and for
+      good reason. As the only dependency type where the platform offsets are
+      not adjacent integers, it requires thinking of a bootstrapping stage
+      <emphasis>two</emphasis> away from the current one. It and its use-case go
+      hand in hand and are both considered poor form: try to not need this sort
+      of dependency, and try to avoid building standard libraries and runtimes
+      in the same derivation as the compiler produces code using them. Instead
+      strive to build those like a normal library, using the newly-built
+      compiler just as a normal library would. In short, do not use this
+      attribute unless you are packaging a compiler and are sure it is needed.
+     </para>
+     <para>
+      Since these packages are able to run at build time, they are added to the
+      <envar>PATH</envar>, as described above. But since these packages are only
+      guaranteed to be able to run then, they shouldn't persist as run-time
+      dependencies. This isn't currently enforced, but could be in the future.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>depsHostHost</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of dependencies whose host and target platforms match the new
+      derivation's host platform. This means a <literal>0</literal> host offset
+      and <literal>0</literal> target offset from the new derivation's host
+      platform. These are packages used at run-time to generate code also used
+      at run-time. In practice, this would usually be tools used by compilers
+      for macros or a metaprogramming system, or libraries used by the macros or
+      metaprogramming code itself. It's always preferable to use a
+      <varname>depsBuildBuild</varname> dependency in the derivation being built
+      over a <varname>depsHostHost</varname> on the tool doing the building for
+      this purpose.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>buildInputs</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of dependencies whose host platform and target platform match the
+      new derivation's. This means a <literal>0</literal> host offset and a
+      <literal>1</literal> target offset from the new derivation's host
+      platform. This would be called <varname>depsHostTarget</varname> but for
+      historical continuity. If the dependency doesn't care about the target
+      platform (i.e. isn't a compiler or similar tool), put it here, rather than
+      in <varname>depsBuildBuild</varname>.
+     </para>
+     <para>
+      These are often programs and libraries used by the new derivation at
+      <emphasis>run</emphasis>-time, but that isn't always the case. For
+      example, the machine code in a statically-linked library is only used at
+      run-time, but the derivation containing the library is only needed at
+      build-time. Even in the dynamic case, the library may also be needed at
+      build-time to appease the linker.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>depsTargetTarget</varname>
+    </term>
+    <listitem>
+     <para>
+      A list of dependencies whose host platform matches the new derivation's
+      target platform. This means a <literal>1</literal> offset from the new
+      derivation's platforms. These are packages that run on the target
+      platform, e.g. the standard library or run-time deps of standard library
+      that a compiler insists on knowing about. It's poor form in almost all
+      cases for a package to depend on another from a future stage [future
+      stage corresponding to positive offset]. Do not use this attribute unless
+      you are packaging a compiler and are sure it is needed.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>depsBuildBuildPropagated</varname>
+    </term>
+    <listitem>
+     <para>
+      The propagated equivalent of <varname>depsBuildBuild</varname>. This
+      perhaps never ought to be used, but it is included for consistency [see
+      below for the others].
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>propagatedNativeBuildInputs</varname>
+    </term>
+    <listitem>
+     <para>
+      The propagated equivalent of <varname>nativeBuildInputs</varname>. This
+      would be called <varname>depsBuildHostPropagated</varname> but for
+      historical continuity. For example, if package <varname>Y</varname> has
+      <literal>propagatedNativeBuildInputs = [X]</literal>, and package
+      <varname>Z</varname> has <literal>buildInputs = [Y]</literal>, then
+      package <varname>Z</varname> will be built as if it included package
+      <varname>X</varname> in its <varname>nativeBuildInputs</varname>. If
+      instead, package <varname>Z</varname> has <literal>nativeBuildInputs =
+      [Y]</literal>, then <varname>Z</varname> will be built as if it included
+      <varname>X</varname> in the <varname>depsBuildBuild</varname> of package
+      <varname>Z</varname>, because of the sum of the two <literal>-1</literal>
+      host offsets.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>depsBuildTargetPropagated</varname>
+    </term>
+    <listitem>
+     <para>
+      The propagated equivalent of <varname>depsBuildTarget</varname>. This is
+      prefixed for the same reason of alerting potential users.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>depsHostHostPropagated</varname>
+    </term>
+    <listitem>
+     <para>
+      The propagated equivalent of <varname>depsHostHost</varname>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>propagatedBuildInputs</varname>
+    </term>
+    <listitem>
+     <para>
+      The propagated equivalent of <varname>buildInputs</varname>. This would
+      be called <varname>depsHostTargetPropagated</varname> but for historical
+      continuity.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>depsTargetTargetPropagated</varname>
+    </term>
+    <listitem>
+     <para>
+      The propagated equivalent of <varname>depsTargetTarget</varname>. This is
+      prefixed for the same reason of alerting potential users.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+ </section>
+ <section xml:id="ssec-stdenv-attributes">
+  <title>Attributes</title>
+
+  <variablelist>
+   <title>Variables affecting <literal>stdenv</literal> initialisation</title>
+   <varlistentry>
+    <term>
+     <varname>NIX_DEBUG</varname>
+    </term>
+    <listitem>
+     <para>
+      A natural number indicating how much information to log. If set to 1 or
+      higher, <literal>stdenv</literal> will print moderate debugging
+      information during the build. In particular, the <command>gcc</command>
+      and <command>ld</command> wrapper scripts will print out the complete
+      command line passed to the wrapped tools. If set to 6 or higher, the
+      <literal>stdenv</literal> setup script will be run with <literal>set
+      -x</literal> tracing. If set to 7 or higher, the <command>gcc</command>
+      and <command>ld</command> wrapper scripts will also be run with
+      <literal>set -x</literal> tracing.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <variablelist>
+   <title>Attributes affecting build properties</title>
+   <varlistentry>
+    <term>
+     <varname>enableParallelBuilding</varname>
+    </term>
+    <listitem>
+     <para>
+      If set to <literal>true</literal>, <literal>stdenv</literal> will pass
+      specific flags to <literal>make</literal> and other build tools to enable
+      parallel building with up to <literal>build-cores</literal> workers.
+     </para>
+     <para>
+      Unless set to <literal>false</literal>, some build systems with good
+      support for parallel building including <literal>cmake</literal>,
+      <literal>meson</literal>, and <literal>qmake</literal> will set it to
+      <literal>true</literal>.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <variablelist>
+   <title>Special variables</title>
+   <varlistentry>
+    <term>
+     <varname>passthru</varname>
+    </term>
+    <listitem>
+     <para>
+      This is an attribute set which can be filled with arbitrary values. For
+      example:
+<programlisting>
+passthru = {
+  foo = "bar";
+  baz = {
+    value1 = 4;
+    value2 = 5;
+  };
+}
+</programlisting>
+     </para>
+     <para>
+      Values inside it are not passed to the builder, so you can change them
+      without triggering a rebuild. However, they can be accessed outside of a
+      derivation directly, as if they were set inside a derivation itself, e.g.
+      <literal>hello.baz.value1</literal>. We don't specify any usage or schema
+      of <literal>passthru</literal> - it is meant for values that would be
+      useful outside the derivation in other parts of a Nix expression (e.g. in
+      other derivations). An example would be to convey some specific dependency
+      of your derivation which contains a program with plugins support. Later,
+      others who make derivations with plugins can use passed-through dependency
+      to ensure that their plugin would be binary-compatible with built program.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>passthru.updateScript</varname>
+    </term>
+    <listitem>
+     <para>
+      A script to be run by <filename>maintainers/scripts/update.nix</filename> when
+      the package is matched. It needs to be an executable file, either on the file
+      system:
+<programlisting>
+passthru.updateScript = ./update.sh;
+</programlisting>
+      or inside the expression itself:
+<programlisting>
+passthru.updateScript = writeScript "update-zoom-us" ''
+  #!/usr/bin/env nix-shell
+  #!nix-shell -i bash -p curl pcre common-updater-scripts
+
+  set -eu -o pipefail
+
+  version="$(curl -sI https://zoom.us/client/latest/zoom_x86_64.tar.xz | grep -Fi 'Location:' | pcregrep -o1 '/(([0-9]\.?)+)/')"
+  update-source-version zoom-us "$version"
+'';
+</programlisting>
+      The attribute can also contain a list, a script followed by arguments to be passed to it:
+<programlisting>
+passthru.updateScript = [ ../../update.sh pname "--requested-release=unstable" ];
+</programlisting>
+      Note that the update scripts will be run in parallel by default; you should avoid running <command>git commit</command> or any other commands that cannot handle that.
+     </para>
+
+     <para>
+      For information about how to run the updates, execute
+      <cmdsynopsis><command>nix-shell</command> <arg>maintainers/scripts/update.nix</arg></cmdsynopsis>.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+ </section>
+ <section xml:id="sec-stdenv-phases">
+  <title>Phases</title>
+
+  <para>
+   The generic builder has a number of <emphasis>phases</emphasis>. Package
+   builds are split into phases to make it easier to override specific parts of
+   the build (e.g., unpacking the sources or installing the binaries).
+   Furthermore, it allows a nicer presentation of build logs in the Nix build
+   farm.
+  </para>
+
+  <para>
+   Each phase can be overridden in its entirety either by setting the
+   environment variable <varname><replaceable>name</replaceable>Phase</varname>
+   to a string containing some shell commands to be executed, or by redefining
+   the shell function <varname><replaceable>name</replaceable>Phase</varname>.
+   The former is convenient to override a phase from the derivation, while the
+   latter is convenient from a build script. However, typically one only wants
+   to <emphasis>add</emphasis> some commands to a phase, e.g. by defining
+   <literal>postInstall</literal> or <literal>preFixup</literal>, as skipping
+   some of the default actions may have unexpected consequences.
+  </para>
+
+  <section xml:id="ssec-controlling-phases">
+   <title>Controlling phases</title>
+
+   <para>
+    There are a number of variables that control what phases are executed and
+    in what order:
+    <variablelist>
+     <title>Variables affecting phase control</title>
+     <varlistentry>
+      <term>
+       <varname>phases</varname>
+      </term>
+      <listitem>
+       <para>
+        Specifies the phases. You can change the order in which phases are
+        executed, or add new phases, by setting this variable. If it’s not
+        set, the default value is used, which is <literal>$prePhases
+        unpackPhase patchPhase $preConfigurePhases configurePhase
+        $preBuildPhases buildPhase checkPhase $preInstallPhases installPhase
+        fixupPhase $preDistPhases distPhase $postPhases</literal>.
+       </para>
+       <para>
+        Usually, if you just want to add a few phases, it’s more convenient
+        to set one of the variables below (such as
+        <varname>preInstallPhases</varname>), as you then don’t specify all
+        the normal phases.
+       </para>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       <varname>prePhases</varname>
+      </term>
+      <listitem>
+       <para>
+        Additional phases executed before any of the default phases.
+       </para>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       <varname>preConfigurePhases</varname>
+      </term>
+      <listitem>
+       <para>
+        Additional phases executed just before the configure phase.
+       </para>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       <varname>preBuildPhases</varname>
+      </term>
+      <listitem>
+       <para>
+        Additional phases executed just before the build phase.
+       </para>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       <varname>preInstallPhases</varname>
+      </term>
+      <listitem>
+       <para>
+        Additional phases executed just before the install phase.
+       </para>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       <varname>preFixupPhases</varname>
+      </term>
+      <listitem>
+       <para>
+        Additional phases executed just before the fixup phase.
+       </para>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       <varname>preDistPhases</varname>
+      </term>
+      <listitem>
+       <para>
+        Additional phases executed just before the distribution phase.
+       </para>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       <varname>postPhases</varname>
+      </term>
+      <listitem>
+       <para>
+        Additional phases executed after any of the default phases.
+       </para>
+      </listitem>
+     </varlistentry>
+    </variablelist>
+   </para>
+  </section>
+
+  <section xml:id="ssec-unpack-phase">
+   <title>The unpack phase</title>
+
+   <para>
+    The unpack phase is responsible for unpacking the source code of the
+    package. The default implementation of <function>unpackPhase</function>
+    unpacks the source files listed in the <envar>src</envar> environment
+    variable to the current directory. It supports the following files by
+    default:
+    <variablelist>
+     <varlistentry>
+      <term>
+       Tar files
+      </term>
+      <listitem>
+       <para>
+        These can optionally be compressed using <command>gzip</command>
+        (<filename>.tar.gz</filename>, <filename>.tgz</filename> or
+        <filename>.tar.Z</filename>), <command>bzip2</command>
+        (<filename>.tar.bz2</filename>, <filename>.tbz2</filename> or
+        <filename>.tbz</filename>) or <command>xz</command>
+        (<filename>.tar.xz</filename>, <filename>.tar.lzma</filename> or
+        <filename>.txz</filename>).
+       </para>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       Zip files
+      </term>
+      <listitem>
+       <para>
+        Zip files are unpacked using <command>unzip</command>. However,
+        <command>unzip</command> is not in the standard environment, so you
+        should add it to <varname>nativeBuildInputs</varname> yourself.
+       </para>
+      </listitem>
+     </varlistentry>
+     <varlistentry>
+      <term>
+       Directories in the Nix store
+      </term>
+      <listitem>
+       <para>
+        These are simply copied to the current directory. The hash part of the
+        file name is stripped, e.g.
+        <filename>/nix/store/1wydxgby13cz...-my-sources</filename> would be
+        copied to <filename>my-sources</filename>.
+       </para>
+      </listitem>
+     </varlistentry>
+    </variablelist>
+    Additional file types can be supported by setting the
+    <varname>unpackCmd</varname> variable (see below).
+   </para>
+
+   <para></para>
+
+   <variablelist>
+    <title>Variables controlling the unpack phase</title>
+    <varlistentry>
+     <term>
+      <varname>srcs</varname> / <varname>src</varname>
+     </term>
+     <listitem>
+      <para>
+       The list of source files or directories to be unpacked or copied. One of
+       these must be set.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>sourceRoot</varname>
+     </term>
+     <listitem>
+      <para>
+       After running <function>unpackPhase</function>, the generic builder
+       changes the current directory to the directory created by unpacking the
+       sources. If there are multiple source directories, you should set
+       <varname>sourceRoot</varname> to the name of the intended directory.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>setSourceRoot</varname>
+     </term>
+     <listitem>
+      <para>
+       Alternatively to setting <varname>sourceRoot</varname>, you can set
+       <varname>setSourceRoot</varname> to a shell command to be evaluated by
+       the unpack phase after the sources have been unpacked. This command must
+       set <varname>sourceRoot</varname>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>preUnpack</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the start of the unpack phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>postUnpack</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the end of the unpack phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontMakeSourcesWritable</varname>
+     </term>
+     <listitem>
+      <para>
+       If set to <literal>1</literal>, the unpacked sources are
+       <emphasis>not</emphasis> made writable. By default, they are made
+       writable to prevent problems with read-only sources. For example, copied
+       store directories would be read-only without this.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>unpackCmd</varname>
+     </term>
+     <listitem>
+      <para>
+       The unpack phase evaluates the string <literal>$unpackCmd</literal> for
+       any unrecognised file. The path to the current source file is contained
+       in the <varname>curSrc</varname> variable.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="ssec-patch-phase">
+   <title>The patch phase</title>
+
+   <para>
+    The patch phase applies the list of patches defined in the
+    <varname>patches</varname> variable.
+   </para>
+
+   <variablelist>
+    <title>Variables controlling the patch phase</title>
+    <varlistentry>
+     <term>
+      <varname>patches</varname>
+     </term>
+     <listitem>
+      <para>
+       The list of patches. They must be in the format accepted by the
+       <command>patch</command> command, and may optionally be compressed using
+       <command>gzip</command> (<filename>.gz</filename>),
+       <command>bzip2</command> (<filename>.bz2</filename>) or
+       <command>xz</command> (<filename>.xz</filename>).
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>patchFlags</varname>
+     </term>
+     <listitem>
+      <para>
+       Flags to be passed to <command>patch</command>. If not set, the argument
+       <option>-p1</option> is used, which causes the leading directory
+       component to be stripped from the file names in each patch.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>prePatch</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the start of the patch phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>postPatch</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the end of the patch phase.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="ssec-configure-phase">
+   <title>The configure phase</title>
+
+   <para>
+    The configure phase prepares the source tree for building. The default
+    <function>configurePhase</function> runs <filename>./configure</filename>
+    (typically an Autoconf-generated script) if it exists.
+   </para>
+
+   <variablelist>
+    <title>Variables controlling the configure phase</title>
+    <varlistentry>
+     <term>
+      <varname>configureScript</varname>
+     </term>
+     <listitem>
+      <para>
+       The name of the configure script. It defaults to
+       <filename>./configure</filename> if it exists; otherwise, the configure
+       phase is skipped. This can actually be a command (like <literal>perl
+       ./Configure.pl</literal>).
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>configureFlags</varname>
+     </term>
+     <listitem>
+      <para>
+       A list of strings passed as additional arguments to the configure
+       script.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>configureFlagsArray</varname>
+     </term>
+     <listitem>
+      <para>
+       A shell array containing additional arguments passed to the configure
+       script. You must use this instead of <varname>configureFlags</varname>
+       if the arguments contain spaces.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontAddPrefix</varname>
+     </term>
+     <listitem>
+      <para>
+       By default, the flag <literal>--prefix=$prefix</literal> is added to the
+       configure flags. If this is undesirable, set this variable to true.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>prefix</varname>
+     </term>
+     <listitem>
+      <para>
+       The prefix under which the package must be installed, passed via the
+       <option>--prefix</option> option to the configure script. It defaults to
+       <option>$out</option>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>prefixKey</varname>
+     </term>
+     <listitem>
+      <para>
+       The key to use when specifying the prefix. By default, this is set to
+       <option>--prefix=</option> as that is used by the majority of packages.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontAddDisableDepTrack</varname>
+     </term>
+     <listitem>
+      <para>
+       By default, the flag <literal>--disable-dependency-tracking</literal> is
+       added to the configure flags to speed up Automake-based builds. If this
+       is undesirable, set this variable to true.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontFixLibtool</varname>
+     </term>
+     <listitem>
+      <para>
+       By default, the configure phase applies some special hackery to all
+       files called <filename>ltmain.sh</filename> before running the configure
+       script in order to improve the purity of Libtool-based packages
+       <footnote xml:id="footnote-stdenv-sys-lib-search-path">
+        <para>
+         It clears the
+         <varname>sys_lib_<replaceable>*</replaceable>search_path</varname>
+         variables in the Libtool script to prevent Libtool from using
+         libraries in <filename>/usr/lib</filename> and such.
+        </para>
+       </footnote>
+       . If this is undesirable, set this variable to true.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontDisableStatic</varname>
+     </term>
+     <listitem>
+      <para>
+       By default, when the configure script has
+       <option>--enable-static</option>, the option
+       <option>--disable-static</option> is added to the configure flags.
+      </para>
+      <para>
+       If this is undesirable, set this variable to true.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>configurePlatforms</varname>
+     </term>
+     <listitem>
+      <para>
+       By default, when cross compiling, the configure script has
+       <option>--build=...</option> and <option>--host=...</option> passed.
+       Packages can instead pass <literal>[ "build" "host" "target" ]</literal>
+       or a subset to control exactly which platform flags are passed. Compilers
+       and other tools can use this to also pass the target platform.
+       <footnote xml:id="footnote-stdenv-build-time-guessing-impurity">
+        <para>
+         Eventually these will be passed building natively as well, to improve
+         determinism: build-time guessing, as is done today, is a risk of
+         impurity.
+        </para>
+       </footnote>
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>preConfigure</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the start of the configure phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>postConfigure</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the end of the configure phase.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="build-phase">
+   <title>The build phase</title>
+
+   <para>
+    The build phase is responsible for actually building the package (e.g.
+    compiling it). The default <function>buildPhase</function> simply calls
+    <command>make</command> if a file named <filename>Makefile</filename>,
+    <filename>makefile</filename> or <filename>GNUmakefile</filename> exists in
+    the current directory (or the <varname>makefile</varname> is explicitly
+    set); otherwise it does nothing.
+   </para>
+
+   <variablelist>
+    <title>Variables controlling the build phase</title>
+    <varlistentry>
+     <term>
+      <varname>dontBuild</varname>
+     </term>
+     <listitem>
+      <para>
+       Set to true to skip the build phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>makefile</varname>
+     </term>
+     <listitem>
+      <para>
+       The file name of the Makefile.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>makeFlags</varname>
+     </term>
+     <listitem>
+      <para>
+       A list of strings passed as additional flags to <command>make</command>.
+       These flags are also used by the default install and check phase. For
+       setting make flags specific to the build phase, use
+       <varname>buildFlags</varname> (see below).
+<programlisting>
+makeFlags = [ "PREFIX=$(out)" ];
+</programlisting>
+       <note>
+        <para>
+         The flags are quoted in bash, but environment variables can be
+         specified by using the make syntax.
+        </para>
+       </note>
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>makeFlagsArray</varname>
+     </term>
+     <listitem>
+      <para>
+       A shell array containing additional arguments passed to
+       <command>make</command>. You must use this instead of
+       <varname>makeFlags</varname> if the arguments contain spaces, e.g.
+<programlisting>
+makeFlagsArray=(CFLAGS="-O0 -g" LDFLAGS="-lfoo -lbar")
+</programlisting>
+       Note that shell arrays cannot be passed through environment variables,
+       so you cannot set <varname>makeFlagsArray</varname> in a derivation
+       attribute (because those are passed through environment variables): you
+       have to define them in shell code.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>buildFlags</varname> / <varname>buildFlagsArray</varname>
+     </term>
+     <listitem>
+      <para>
+       A list of strings passed as additional flags to <command>make</command>.
+       Like <varname>makeFlags</varname> and <varname>makeFlagsArray</varname>,
+       but only used by the build phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>preBuild</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the start of the build phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>postBuild</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the end of the build phase.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+
+   <para>
+    You can set flags for <command>make</command> through the
+    <varname>makeFlags</varname> variable.
+   </para>
+
+   <para>
+    Before and after running <command>make</command>, the hooks
+    <varname>preBuild</varname> and <varname>postBuild</varname> are called,
+    respectively.
+   </para>
+  </section>
+
+  <section xml:id="ssec-check-phase">
+   <title>The check phase</title>
+
+   <para>
+    The check phase checks whether the package was built correctly by running
+    its test suite. The default <function>checkPhase</function> calls
+    <command>make check</command>, but only if the <varname>doCheck</varname>
+    variable is enabled.
+   </para>
+
+   <variablelist>
+    <title>Variables controlling the check phase</title>
+    <varlistentry>
+     <term>
+      <varname>doCheck</varname>
+     </term>
+     <listitem>
+      <para>
+       Controls whether the check phase is executed. By default it is skipped,
+       but if <varname>doCheck</varname> is set to true, the check phase is
+       usually executed. Thus you should set
+<programlisting>doCheck = true;</programlisting>
+       in the derivation to enable checks. The exception is cross compilation.
+       Cross compiled builds never run tests, no matter how
+       <varname>doCheck</varname> is set, as the newly-built program won't run
+       on the platform used to build it.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>makeFlags</varname> / <varname>makeFlagsArray</varname> / <varname>makefile</varname>
+     </term>
+     <listitem>
+      <para>
+       See the build phase for details.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>checkTarget</varname>
+     </term>
+     <listitem>
+      <para>
+       The make target that runs the tests. Defaults to
+       <literal>check</literal>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>checkFlags</varname> / <varname>checkFlagsArray</varname>
+     </term>
+     <listitem>
+      <para>
+       A list of strings passed as additional flags to <command>make</command>.
+       Like <varname>makeFlags</varname> and <varname>makeFlagsArray</varname>,
+       but only used by the check phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>checkInputs</varname>
+     </term>
+     <listitem>
+      <para>
+       A list of dependencies used by the phase. This gets included in
+       <varname>nativeBuildInputs</varname> when <varname>doCheck</varname> is
+       set.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>preCheck</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the start of the check phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>postCheck</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the end of the check phase.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="ssec-install-phase">
+   <title>The install phase</title>
+
+   <para>
+    The install phase is responsible for installing the package in the Nix
+    store under <envar>out</envar>. The default
+    <function>installPhase</function> creates the directory
+    <literal>$out</literal> and calls <command>make install</command>.
+   </para>
+
+   <variablelist>
+    <title>Variables controlling the install phase</title>
+    <varlistentry>
+     <term>
+      <varname>makeFlags</varname> / <varname>makeFlagsArray</varname> / <varname>makefile</varname>
+     </term>
+     <listitem>
+      <para>
+       See the build phase for details.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>installTargets</varname>
+     </term>
+     <listitem>
+      <para>
+       The make targets that perform the installation. Defaults to
+       <literal>install</literal>. Example:
+<programlisting>
+installTargets = "install-bin install-doc";</programlisting>
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>installFlags</varname> / <varname>installFlagsArray</varname>
+     </term>
+     <listitem>
+      <para>
+       A list of strings passed as additional flags to <command>make</command>.
+       Like <varname>makeFlags</varname> and <varname>makeFlagsArray</varname>,
+       but only used by the install phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>preInstall</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the start of the install phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>postInstall</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the end of the install phase.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="ssec-fixup-phase">
+   <title>The fixup phase</title>
+
+   <para>
+    The fixup phase performs some (Nix-specific) post-processing actions on the
+    files installed under <filename>$out</filename> by the install phase. The
+    default <function>fixupPhase</function> does the following:
+    <itemizedlist>
+     <listitem>
+      <para>
+       It moves the <filename>man/</filename>, <filename>doc/</filename> and
+       <filename>info/</filename> subdirectories of <envar>$out</envar> to
+       <filename>share/</filename>.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       It strips libraries and executables of debug information.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       On Linux, it applies the <command>patchelf</command> command to ELF
+       executables and libraries to remove unused directories from the
+       <literal>RPATH</literal> in order to prevent unnecessary runtime
+       dependencies.
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       It rewrites the interpreter paths of shell scripts to paths found in
+       <envar>PATH</envar>. E.g., <filename>/usr/bin/perl</filename> will be
+       rewritten to
+       <filename>/nix/store/<replaceable>some-perl</replaceable>/bin/perl</filename>
+       found in <envar>PATH</envar>.
+      </para>
+     </listitem>
+    </itemizedlist>
+   </para>
+
+   <variablelist>
+    <title>Variables controlling the fixup phase</title>
+    <varlistentry>
+     <term>
+      <varname>dontStrip</varname>
+     </term>
+     <listitem>
+      <para>
+       If set, libraries and executables are not stripped. By default, they
+       are.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontStripHost</varname>
+     </term>
+     <listitem>
+      <para>
+       Like <varname>dontStripHost</varname>, but only affects the
+       <command>strip</command> command targetting the package's host platform.
+       Useful when supporting cross compilation, but otherwise feel free to
+       ignore.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontStripTarget</varname>
+     </term>
+     <listitem>
+      <para>
+       Like <varname>dontStripHost</varname>, but only affects the
+       <command>strip</command> command targetting the packages' target
+       platform. Useful when supporting cross compilation, but otherwise feel
+       free to ignore.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontMoveSbin</varname>
+     </term>
+     <listitem>
+      <para>
+       If set, files in <filename>$out/sbin</filename> are not moved to
+       <filename>$out/bin</filename>. By default, they are.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>stripAllList</varname>
+     </term>
+     <listitem>
+      <para>
+       List of directories to search for libraries and executables from which
+       <emphasis>all</emphasis> symbols should be stripped. By default, it’s
+       empty. Stripping all symbols is risky, since it may remove not just
+       debug symbols but also ELF information necessary for normal execution.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>stripAllFlags</varname>
+     </term>
+     <listitem>
+      <para>
+       Flags passed to the <command>strip</command> command applied to the
+       files in the directories listed in <varname>stripAllList</varname>.
+       Defaults to <option>-s</option> (i.e. <option>--strip-all</option>).
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>stripDebugList</varname>
+     </term>
+     <listitem>
+      <para>
+       List of directories to search for libraries and executables from which
+       only debugging-related symbols should be stripped. It defaults to
+       <literal>lib bin sbin</literal>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>stripDebugFlags</varname>
+     </term>
+     <listitem>
+      <para>
+       Flags passed to the <command>strip</command> command applied to the
+       files in the directories listed in <varname>stripDebugList</varname>.
+       Defaults to <option>-S</option> (i.e. <option>--strip-debug</option>).
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontPatchELF</varname>
+     </term>
+     <listitem>
+      <para>
+       If set, the <command>patchelf</command> command is not used to remove
+       unnecessary <literal>RPATH</literal> entries. Only applies to Linux.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontPatchShebangs</varname>
+     </term>
+     <listitem>
+      <para>
+       If set, scripts starting with <literal>#!</literal> do not have their
+       interpreter paths rewritten to paths in the Nix store.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>forceShare</varname>
+     </term>
+     <listitem>
+      <para>
+       The list of directories that must be moved from
+       <filename>$out</filename> to <filename>$out/share</filename>. Defaults
+       to <literal>man doc info</literal>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>setupHook</varname>
+     </term>
+     <listitem>
+      <para>
+       A package can export a <link linkend="ssec-setup-hooks">setup hook</link>
+       by setting this variable. The setup hook, if defined, is copied to
+       <filename>$out/nix-support/setup-hook</filename>. Environment variables
+       are then substituted in it using <function
+       linkend="fun-substituteAll">substituteAll</function>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>preFixup</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the start of the fixup phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>postFixup</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the end of the fixup phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry xml:id="stdenv-separateDebugInfo">
+     <term>
+      <varname>separateDebugInfo</varname>
+     </term>
+     <listitem>
+      <para>
+       If set to <literal>true</literal>, the standard environment will enable
+       debug information in C/C++ builds. After installation, the debug
+       information will be separated from the executables and stored in the
+       output named <literal>debug</literal>. (This output is enabled
+       automatically; you don’t need to set the <varname>outputs</varname>
+       attribute explicitly.) To be precise, the debug information is stored in
+       <filename><replaceable>debug</replaceable>/lib/debug/.build-id/<replaceable>XX</replaceable>/<replaceable>YYYY…</replaceable></filename>,
+       where <replaceable>XXYYYY…</replaceable> is the <replaceable>build
+       ID</replaceable> of the binary — a SHA-1 hash of the contents of the
+       binary. Debuggers like GDB use the build ID to look up the separated
+       debug information.
+      </para>
+      <para>
+       For example, with GDB, you can add
+<programlisting>
+set debug-file-directory ~/.nix-profile/lib/debug
+</programlisting>
+       to <filename>~/.gdbinit</filename>. GDB will then be able to find debug
+       information installed via <literal>nix-env -i</literal>.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="ssec-installCheck-phase">
+   <title>The installCheck phase</title>
+
+   <para>
+    The installCheck phase checks whether the package was installed correctly
+    by running its test suite against the installed directories. The default
+    <function>installCheck</function> calls <command>make
+    installcheck</command>.
+   </para>
+
+   <variablelist>
+    <title>Variables controlling the installCheck phase</title>
+    <varlistentry>
+     <term>
+      <varname>doInstallCheck</varname>
+     </term>
+     <listitem>
+      <para>
+       Controls whether the installCheck phase is executed. By default it is
+       skipped, but if <varname>doInstallCheck</varname> is set to true, the
+       installCheck phase is usually executed. Thus you should set
+<programlisting>doInstallCheck = true;</programlisting>
+       in the derivation to enable install checks. The exception is cross
+       compilation. Cross compiled builds never run tests, no matter how
+       <varname>doInstallCheck</varname> is set, as the newly-built program
+       won't run on the platform used to build it.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>installCheckTarget</varname>
+     </term>
+     <listitem>
+      <para>
+       The make target that runs the install tests. Defaults to
+       <literal>installcheck</literal>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>installCheckFlags</varname> / <varname>installCheckFlagsArray</varname>
+     </term>
+     <listitem>
+      <para>
+       A list of strings passed as additional flags to <command>make</command>.
+       Like <varname>makeFlags</varname> and <varname>makeFlagsArray</varname>,
+       but only used by the installCheck phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>installCheckInputs</varname>
+     </term>
+     <listitem>
+      <para>
+       A list of dependencies used by the phase. This gets included in
+       <varname>buildInputs</varname> when <varname>doInstallCheck</varname> is
+       set.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>preInstallCheck</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the start of the installCheck phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>postInstallCheck</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the end of the installCheck phase.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+
+  <section xml:id="ssec-distribution-phase">
+   <title>The distribution phase</title>
+
+   <para>
+    The distribution phase is intended to produce a source distribution of the
+    package. The default <function>distPhase</function> first calls
+    <command>make dist</command>, then it copies the resulting source tarballs
+    to <filename>$out/tarballs/</filename>. This phase is only executed if the
+    attribute <varname>doDist</varname> is set.
+   </para>
+
+   <variablelist>
+    <title>Variables controlling the distribution phase</title>
+    <varlistentry>
+     <term>
+      <varname>distTarget</varname>
+     </term>
+     <listitem>
+      <para>
+       The make target that produces the distribution. Defaults to
+       <literal>dist</literal>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>distFlags</varname> / <varname>distFlagsArray</varname>
+     </term>
+     <listitem>
+      <para>
+       Additional flags passed to <command>make</command>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>tarballs</varname>
+     </term>
+     <listitem>
+      <para>
+       The names of the source distribution files to be copied to
+       <filename>$out/tarballs/</filename>. It can contain shell wildcards. The
+       default is <filename>*.tar.gz</filename>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>dontCopyDist</varname>
+     </term>
+     <listitem>
+      <para>
+       If set, no files are copied to <filename>$out/tarballs/</filename>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>preDist</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the start of the distribution phase.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      <varname>postDist</varname>
+     </term>
+     <listitem>
+      <para>
+       Hook executed at the end of the distribution phase.
+      </para>
+     </listitem>
+    </varlistentry>
+   </variablelist>
+  </section>
+ </section>
+ <section xml:id="ssec-stdenv-functions">
+  <title>Shell functions</title>
+
+  <para>
+   The standard environment provides a number of useful functions.
+  </para>
+
+  <variablelist>
+   <varlistentry xml:id='fun-makeWrapper'>
+    <term>
+     <function>makeWrapper</function> <replaceable>executable</replaceable> <replaceable>wrapperfile</replaceable> <replaceable>args</replaceable>
+    </term>
+    <listitem>
+     <para>
+      Constructs a wrapper for a program with various possible arguments. For
+      example:
+<programlisting>
+# adds `FOOBAR=baz` to `$out/bin/foo`’s environment
+makeWrapper $out/bin/foo $wrapperfile --set FOOBAR baz
+
+# prefixes the binary paths of `hello` and `git`
+# Be advised that paths often should be patched in directly
+# (via string replacements or in `configurePhase`).
+makeWrapper $out/bin/foo $wrapperfile --prefix PATH : ${lib.makeBinPath [ hello git ]}
+</programlisting>
+      There’s many more kinds of arguments, they are documented in
+      <literal>nixpkgs/pkgs/build-support/setup-hooks/make-wrapper.sh</literal>.
+     </para>
+     <para>
+      <literal>wrapProgram</literal> is a convenience function you probably
+      want to use most of the time.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry xml:id='fun-substitute'>
+    <term>
+     <function>substitute</function> <replaceable>infile</replaceable> <replaceable>outfile</replaceable> <replaceable>subs</replaceable>
+    </term>
+    <listitem>
+     <para>
+      Performs string substitution on the contents of
+      <replaceable>infile</replaceable>, writing the result to
+      <replaceable>outfile</replaceable>. The substitutions in
+      <replaceable>subs</replaceable> are of the following form:
+      <variablelist>
+       <varlistentry>
+        <term>
+         <option>--replace</option> <replaceable>s1</replaceable> <replaceable>s2</replaceable>
+        </term>
+        <listitem>
+         <para>
+          Replace every occurrence of the string <replaceable>s1</replaceable>
+          by <replaceable>s2</replaceable>.
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         <option>--subst-var</option> <replaceable>varName</replaceable>
+        </term>
+        <listitem>
+         <para>
+          Replace every occurrence of
+          <literal>@<replaceable>varName</replaceable>@</literal> by the
+          contents of the environment variable
+          <replaceable>varName</replaceable>. This is useful for generating
+          files from templates, using
+          <literal>@<replaceable>...</replaceable>@</literal> in the template
+          as placeholders.
+         </para>
+        </listitem>
+       </varlistentry>
+       <varlistentry>
+        <term>
+         <option>--subst-var-by</option> <replaceable>varName</replaceable> <replaceable>s</replaceable>
+        </term>
+        <listitem>
+         <para>
+          Replace every occurrence of
+          <literal>@<replaceable>varName</replaceable>@</literal> by the string
+          <replaceable>s</replaceable>.
+         </para>
+        </listitem>
+       </varlistentry>
+      </variablelist>
+     </para>
+     <para>
+      Example:
+<programlisting>
+substitute ./foo.in ./foo.out \
+    --replace /usr/bin/bar $bar/bin/bar \
+    --replace "a string containing spaces" "some other text" \
+    --subst-var someVar
+</programlisting>
+     </para>
+     <para>
+      <function>substitute</function> is implemented using the
+      <command
+      xlink:href="http://replace.richardlloyd.org.uk/">replace</command>
+      command. Unlike with the <command>sed</command> command, you don’t have
+      to worry about escaping special characters. It supports performing
+      substitutions on binary files (such as executables), though there
+      you’ll probably want to make sure that the replacement string is as
+      long as the replaced string.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry xml:id='fun-substituteInPlace'>
+    <term>
+     <function>substituteInPlace</function> <replaceable>file</replaceable> <replaceable>subs</replaceable>
+    </term>
+    <listitem>
+     <para>
+      Like <function>substitute</function>, but performs the substitutions in
+      place on the file <replaceable>file</replaceable>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry xml:id='fun-substituteAll'>
+    <term>
+     <function>substituteAll</function> <replaceable>infile</replaceable> <replaceable>outfile</replaceable>
+    </term>
+    <listitem>
+     <para>
+      Replaces every occurrence of
+      <literal>@<replaceable>varName</replaceable>@</literal>, where
+      <replaceable>varName</replaceable> is any environment variable, in
+      <replaceable>infile</replaceable>, writing the result to
+      <replaceable>outfile</replaceable>. For instance, if
+      <replaceable>infile</replaceable> has the contents
+<programlisting>
+#! @bash@/bin/sh
+PATH=@coreutils@/bin
+echo @foo@
+</programlisting>
+      and the environment contains
+      <literal>bash=/nix/store/bmwp0q28cf21...-bash-3.2-p39</literal> and
+      <literal>coreutils=/nix/store/68afga4khv0w...-coreutils-6.12</literal>,
+      but does not contain the variable <varname>foo</varname>, then the output
+      will be
+<programlisting>
+#! /nix/store/bmwp0q28cf21...-bash-3.2-p39/bin/sh
+PATH=/nix/store/68afga4khv0w...-coreutils-6.12/bin
+echo @foo@
+</programlisting>
+      That is, no substitution is performed for undefined variables.
+     </para>
+     <para>
+      Environment variables that start with an uppercase letter or an
+      underscore are filtered out, to prevent global variables (like
+      <literal>HOME</literal>) or private variables (like
+      <literal>__ETC_PROFILE_DONE</literal>) from accidentally getting
+      substituted. The variables also have to be valid bash “names”, as
+      defined in the bash manpage (alphanumeric or <literal>_</literal>, must
+      not start with a number).
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry xml:id='fun-substituteAllInPlace'>
+    <term>
+     <function>substituteAllInPlace</function> <replaceable>file</replaceable>
+    </term>
+    <listitem>
+     <para>
+      Like <function>substituteAll</function>, but performs the substitutions
+      in place on the file <replaceable>file</replaceable>.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry xml:id='fun-stripHash'>
+    <term>
+     <function>stripHash</function> <replaceable>path</replaceable>
+    </term>
+    <listitem>
+     <para>
+      Strips the directory and hash part of a store path, outputting the name
+      part to <literal>stdout</literal>. For example:
+<programlisting>
+# prints coreutils-8.24
+stripHash "/nix/store/9s9r019176g7cvn2nvcw41gsp862y6b4-coreutils-8.24"
+</programlisting>
+      If you wish to store the result in another variable, then the following
+      idiom may be useful:
+<programlisting>
+name="/nix/store/9s9r019176g7cvn2nvcw41gsp862y6b4-coreutils-8.24"
+someVar=$(stripHash $name)
+</programlisting>
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry xml:id='fun-wrapProgram'>
+    <term>
+     <function>wrapProgram</function> <replaceable>executable</replaceable> <replaceable>makeWrapperArgs</replaceable>
+    </term>
+    <listitem>
+     <para>
+      Convenience function for <literal>makeWrapper</literal> that
+      automatically creates a sane wrapper file It takes all the same arguments
+      as <literal>makeWrapper</literal>, except for <literal>--argv0</literal>.
+     </para>
+     <para>
+      It cannot be applied multiple times, since it will overwrite the wrapper
+      file.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+ </section>
+ <section xml:id="ssec-setup-hooks">
+  <title>Package setup hooks</title>
+
+  <para>
+   Nix itself considers a build-time dependency as merely something that should
+   previously be built and accessible at build time—packages themselves are
+   on their own to perform any additional setup. In most cases, that is fine,
+   and the downstream derivation can deal with its own dependencies. But for a
+   few common tasks, that would result in almost every package doing the same
+   sort of setup work—depending not on the package itself, but entirely on
+   which dependencies were used.
+  </para>
+
+  <para>
+   In order to alleviate this burden, the <firstterm>setup hook</firstterm>
+   mechanism was written, where any package can include a shell script that [by
+   convention rather than enforcement by Nix], any downstream
+   reverse-dependency will source as part of its build process. That allows the
+   downstream dependency to merely specify its dependencies, and lets those
+   dependencies effectively initialize themselves. No boilerplate mirroring the
+   list of dependencies is needed.
+  </para>
+
+  <para>
+   The setup hook mechanism is a bit of a sledgehammer though: a powerful
+   feature with a broad and indiscriminate area of effect. The combination of
+   its power and implicit use may be expedient, but isn't without costs. Nix
+   itself is unchanged, but the spirit of added dependencies being effect-free
+   is violated even if the letter isn't. For example, if a derivation path is
+   mentioned more than once, Nix itself doesn't care and simply makes sure the
+   dependency derivation is already built just the same—depending is just
+   needing something to exist, and needing is idempotent. However, a dependency
+   specified twice will have its setup hook run twice, and that could easily
+   change the build environment (though a well-written setup hook will therefore
+   strive to be idempotent so this is in fact not observable). More broadly,
+   setup hooks are anti-modular in that multiple dependencies, whether the same
+   or different, should not interfere and yet their setup hooks may well do so.
+  </para>
+
+  <para>
+   The most typical use of the setup hook is actually to add other hooks which
+   are then run (i.e. after all the setup hooks) on each dependency. For
+   example, the C compiler wrapper's setup hook feeds itself flags for each
+   dependency that contains relevant libraries and headers. This is done by
+   defining a bash function, and appending its name to one of
+   <envar>envBuildBuildHooks</envar>`, <envar>envBuildHostHooks</envar>`,
+   <envar>envBuildTargetHooks</envar>`, <envar>envHostHostHooks</envar>`,
+   <envar>envHostTargetHooks</envar>`, or <envar>envTargetTargetHooks</envar>`.
+   These 6 bash variables correspond to the 6 sorts of dependencies by platform
+   (there's 12 total but we ignore the propagated/non-propagated axis).
+  </para>
+
+  <para>
+   Packages adding a hook should not hard code a specific hook, but rather
+   choose a variable <emphasis>relative</emphasis> to how they are included.
+   Returning to the C compiler wrapper example, if the wrapper itself is an
+   <literal>n</literal> dependency, then it only wants to accumulate flags from
+   <literal>n + 1</literal> dependencies, as only those ones match the
+   compiler's target platform. The <envar>hostOffset</envar> variable is defined
+   with the current dependency's host offset <envar>targetOffset</envar> with
+   its target offset, before its setup hook is sourced. Additionally, since most
+   environment hooks don't care about the target platform, that means the setup
+   hook can append to the right bash array by doing something like
+<programlisting language="bash">
+addEnvHooks "$hostOffset" myBashFunction
+  </programlisting>
+  </para>
+
+  <para>
+   The <emphasis>existence</emphasis> of setups hooks has long been documented
+   and packages inside Nixpkgs are free to use this mechanism. Other packages,
+   however, should not rely on these mechanisms not changing between Nixpkgs
+   versions. Because of the existing issues with this system, there's little
+   benefit from mandating it be stable for any period of time.
+  </para>
+
+  <para>
+   Here are some packages that provide a setup hook. Since the mechanism is
+   modular, this probably isn't an exhaustive list. Then again, since the
+   mechanism is only to be used as a last resort, it might be.
+   <variablelist>
+    <varlistentry>
+     <term>
+      Bintools Wrapper
+     </term>
+     <listitem>
+      <para>
+       The Bintools Wrapper wraps the binary utilities for a bunch of
+       miscellaneous purposes. These are GNU Binutils when targetting Linux, and
+       a mix of cctools and GNU binutils for Darwin. [The "Bintools" name is
+       supposed to be a compromise between "Binutils" and "cctools" not denoting
+       any specific implementation.] Specifically, the underlying bintools
+       package, and a C standard library (glibc or Darwin's libSystem, just for
+       the dynamic loader) are all fed in, and dependency finding, hardening
+       (see below), and purity checks for each are handled by the Bintools
+       Wrapper. Packages typically depend on CC Wrapper, which in turn (at run
+       time) depends on the Bintools Wrapper.
+      </para>
+      <para>
+       The Bintools Wrapper was only just recently split off from CC Wrapper, so
+       the division of labor is still being worked out. For example, it
+       shouldn't care about about the C standard library, but just take a
+       derivation with the dynamic loader (which happens to be the glibc on
+       linux). Dependency finding however is a task both wrappers will continue
+       to need to share, and probably the most important to understand. It is
+       currently accomplished by collecting directories of host-platform
+       dependencies (i.e. <varname>buildInputs</varname> and
+       <varname>nativeBuildInputs</varname>) in environment variables. The
+       Bintools Wrapper's setup hook causes any <filename>lib</filename> and
+       <filename>lib64</filename> subdirectories to be added to
+       <envar>NIX_LDFLAGS</envar>. Since the CC Wrapper and the Bintools Wrapper
+       use the same strategy, most of the Bintools Wrapper code is sparsely
+       commented and refers to the CC Wrapper. But the CC Wrapper's code, by
+       contrast, has quite lengthy comments. The Bintools Wrapper merely cites
+       those, rather than repeating them, to avoid falling out of sync.
+      </para>
+      <para>
+       A final task of the setup hook is defining a number of standard
+       environment variables to tell build systems which executables fulfill
+       which purpose. They are defined to just be the base name of the tools,
+       under the assumption that the Bintools Wrapper's binaries will be on the
+       path. Firstly, this helps poorly-written packages, e.g. ones that look
+       for just <command>gcc</command> when <envar>CC</envar> isn't defined yet
+       <command>clang</command> is to be used. Secondly, this helps packages not
+       get confused when cross-compiling, in which case multiple Bintools
+       Wrappers may simultaneously be in use.
+       <footnote xml:id="footnote-stdenv-per-platform-wrapper">
+        <para>
+         Each wrapper targets a single platform, so if binaries for multiple
+         platforms are needed, the underlying binaries must be wrapped multiple
+         times. As this is a property of the wrapper itself, the multiple
+         wrappings are needed whether or not the same underlying binaries can
+         target multiple platforms.
+        </para>
+       </footnote>
+       <envar>BUILD_</envar>- and <envar>TARGET_</envar>-prefixed versions of
+       the normal environment variable are defined for additional Bintools
+       Wrappers, properly disambiguating them.
+      </para>
+      <para>
+       A problem with this final task is that the Bintools Wrapper is honest and
+       defines <envar>LD</envar> as <command>ld</command>. Most packages,
+       however, firstly use the C compiler for linking, secondly use
+       <envar>LD</envar> anyways, defining it as the C compiler, and thirdly,
+       only so define <envar>LD</envar> when it is undefined as a fallback. This
+       triple-threat means Bintools Wrapper will break those packages, as LD is
+       already defined as the actual linker which the package won't override yet
+       doesn't want to use. The workaround is to define, just for the
+       problematic package, <envar>LD</envar> as the C compiler. A good way to
+       do this would be <command>preConfigure = "LD=$CC"</command>.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      CC Wrapper
+     </term>
+     <listitem>
+      <para>
+       The CC Wrapper wraps a C toolchain for a bunch of miscellaneous purposes.
+       Specifically, a C compiler (GCC or Clang), wrapped binary tools, and a C
+       standard library (glibc or Darwin's libSystem, just for the dynamic
+       loader) are all fed in, and dependency finding, hardening (see below),
+       and purity checks for each are handled by the CC Wrapper. Packages
+       typically depend on the CC Wrapper, which in turn (at run-time) depends
+       on the Bintools Wrapper.
+      </para>
+      <para>
+       Dependency finding is undoubtedly the main task of the CC Wrapper. This
+       works just like the Bintools Wrapper, except that any
+       <filename>include</filename> subdirectory of any relevant dependency is
+       added to <envar>NIX_CFLAGS_COMPILE</envar>. The setup hook itself
+       contains some lengthy comments describing the exact convoluted mechanism
+       by which this is accomplished.
+      </para>
+      <para>
+       Similarly, the CC Wrapper follows the Bintools Wrapper in defining
+       standard environment variables with the names of the tools it wraps, for
+       the same reasons described above. Importantly, while it includes a
+       <command>cc</command> symlink to the c compiler for portability, the
+       <envar>CC</envar> will be defined using the compiler's "real name" (i.e.
+       <command>gcc</command> or <command>clang</command>). This helps lousy
+       build systems that inspect on the name of the compiler rather than run
+       it.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      Perl
+     </term>
+     <listitem>
+      <para>
+       Adds the <filename>lib/site_perl</filename> subdirectory of each build
+       input to the <envar>PERL5LIB</envar> environment variable. For instance,
+       if <varname>buildInputs</varname> contains Perl, then the
+       <filename>lib/site_perl</filename> subdirectory of each input is added
+       to the <envar>PERL5LIB</envar> environment variable.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      Python
+     </term>
+     <listitem>
+      <para>
+       Adds the <filename>lib/${python.libPrefix}/site-packages</filename>
+       subdirectory of each build input to the <envar>PYTHONPATH</envar>
+       environment variable.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      pkg-config
+     </term>
+     <listitem>
+      <para>
+       Adds the <filename>lib/pkgconfig</filename> and
+       <filename>share/pkgconfig</filename> subdirectories of each build input
+       to the <envar>PKG_CONFIG_PATH</envar> environment variable.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      Automake
+     </term>
+     <listitem>
+      <para>
+       Adds the <filename>share/aclocal</filename> subdirectory of each build
+       input to the <envar>ACLOCAL_PATH</envar> environment variable.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      Autoconf
+     </term>
+     <listitem>
+      <para>
+       The <varname>autoreconfHook</varname> derivation adds
+       <varname>autoreconfPhase</varname>, which runs autoreconf, libtoolize and
+       automake, essentially preparing the configure script in autotools-based
+       builds. Most autotools-based packages come with the configure script
+       pre-generated, but this hook is necessary for a few packages and when you
+       need to patch the package’s configure scripts.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      libxml2
+     </term>
+     <listitem>
+      <para>
+       Adds every file named <filename>catalog.xml</filename> found under the
+       <filename>xml/dtd</filename> and <filename>xml/xsl</filename>
+       subdirectories of each build input to the
+       <envar>XML_CATALOG_FILES</envar> environment variable.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      teTeX / TeX Live
+     </term>
+     <listitem>
+      <para>
+       Adds the <filename>share/texmf-nix</filename> subdirectory of each build
+       input to the <envar>TEXINPUTS</envar> environment variable.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      Qt 4
+     </term>
+     <listitem>
+      <para>
+       Sets the <envar>QTDIR</envar> environment variable to Qt’s path.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      gdk-pixbuf
+     </term>
+     <listitem>
+      <para>
+       Exports <envar>GDK_PIXBUF_MODULE_FILE</envar> environment variable to the
+       builder. Add librsvg package to <varname>buildInputs</varname> to get svg
+       support.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      GHC
+     </term>
+     <listitem>
+      <para>
+       Creates a temporary package database and registers every Haskell build
+       input in it (TODO: how?).
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      GStreamer
+     </term>
+     <listitem>
+      <para>
+       Adds the GStreamer plugins subdirectory of each build input to the
+       <envar>GST_PLUGIN_SYSTEM_PATH_1_0</envar> or
+       <envar>GST_PLUGIN_SYSTEM_PATH</envar> environment variable.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      paxctl
+     </term>
+     <listitem>
+      <para>
+       Defines the <varname>paxmark</varname> helper for setting per-executable
+       PaX flags on Linux (where it is available by default; on all other
+       platforms, <varname>paxmark</varname> is a no-op). For example, to
+       disable secure memory protections on the executable
+       <replaceable>foo</replaceable>
+<programlisting>
+      postFixup = ''
+        paxmark m $out/bin/<replaceable>foo</replaceable>
+      '';
+    </programlisting>
+       The <literal>m</literal> flag is the most common flag and is typically
+       required for applications that employ JIT compilation or otherwise need
+       to execute code generated at run-time. Disabling PaX protections should
+       be considered a last resort: if possible, problematic features should be
+       disabled or patched to work with PaX.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      autoPatchelfHook
+     </term>
+     <listitem>
+      <para>
+       This is a special setup hook which helps in packaging proprietary
+       software in that it automatically tries to find missing shared library
+       dependencies of ELF files based on the given
+       <varname>buildInputs</varname> and <varname>nativeBuildInputs</varname>.
+      </para>
+      <para>
+       You can also specify a <envar>runtimeDependencies</envar> environment
+       variable which lists dependencies that are unconditionally added to all
+       executables.
+      </para>
+      <para>
+       This is useful for programs that use <citerefentry>
+        <refentrytitle>dlopen</refentrytitle>
+        <manvolnum>3</manvolnum>
+       </citerefentry> to load libraries at runtime.
+      </para>
+      <para>
+        In certain situations you may want to run the main command
+        (<command>autoPatchelf</command>) of the setup hook on a file or a set
+        of directories instead of unconditionally patching all outputs. This
+        can be done by setting the <envar>dontAutoPatchelf</envar> environment
+        variable to a non-empty value.
+      </para>
+      <para>
+        The <command>autoPatchelf</command> command also recognizes a
+        <parameter class="command">--no-recurse</parameter> command line flag,
+        which prevents it from recursing into subdirectories.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      breakpointHook
+     </term>
+     <listitem>
+      <para>
+       This hook will make a build pause instead of stopping when a failure
+       happens. It prevents nix from cleaning up the build environment immediately and
+       allows the user to attach to a build environment using the
+       <command>cntr</command> command. Upon build error it will print
+       instructions on how to use <command>cntr</command>. Installing
+       cntr and running the command will provide shell access to the build
+       sandbox of failed build. At <filename>/var/lib/cntr</filename> the
+       sandboxed filesystem is mounted. All commands and files of the system are
+       still accessible within the shell. To execute commands from the sandbox
+       use the cntr exec subcommand. Note that <command>cntr</command> also
+       needs to be executed on the machine that is doing the build, which might
+       not be the case when remote builders are enabled.
+       <command>cntr</command> is only supported on Linux-based platforms. To
+       use it first add <literal>cntr</literal> to your
+       <literal>environment.systemPackages</literal> on NixOS or alternatively to
+       the root user on non-NixOS systems. Then in the package that is supposed
+       to be inspected, add <literal>breakpointHook</literal> to
+       <literal>nativeBuildInputs</literal>.
+<programlisting>
+         nativeBuildInputs = [ breakpointHook ];
+       </programlisting>
+       When a build failure happens there will be an instruction printed that
+       shows how to attach with <literal>cntr</literal> to the build sandbox.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      libiconv, libintl
+     </term>
+     <listitem>
+       <para>
+	 A few libraries automatically add to
+	 <literal>NIX_LDFLAGS</literal> their library, making their
+	 symbols automatically available to the linker. This includes
+	 libiconv and libintl (gettext). This is done to provide
+	 compatibility between GNU Linux, where libiconv and libintl
+	 are bundled in, and other systems where that might not be the
+	 case. Sometimes, this behavior is not desired. To disable
+	 this behavior, set <literal>dontAddExtraLibs</literal>.
+       </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      cmake
+     </term>
+     <listitem>
+       <para>
+         Overrides the default configure phase to run the CMake command. By
+	 default, we use the Make generator of CMake. In
+         addition, dependencies are added automatically to CMAKE_PREFIX_PATH so
+         that packages are correctly detected by CMake. Some additional flags
+         are passed in to give similar behavior to configure-based packages. You
+         can disable this hook’s behavior by setting configurePhase to a custom
+         value, or by setting dontUseCmakeConfigure. cmakeFlags controls flags
+         passed only to CMake. By default, parallel building is enabled as CMake
+         supports parallel building almost everywhere. When Ninja is also in
+	 use, CMake will detect that and use the ninja generator.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      xcbuildHook
+     </term>
+     <listitem>
+       <para>
+	 Overrides the build and install phases to run the “xcbuild” command.
+	 This hook is needed when a project only comes with build files for the
+	 XCode build system. You can disable this behavior by setting buildPhase
+	 and configurePhase to a custom value. xcbuildFlags controls flags
+	 passed only to xcbuild.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      meson
+     </term>
+     <listitem>
+       <para>
+	 Overrides the configure phase to run meson to generate Ninja files. You
+	 can disable this behavior by setting configurePhase to a custom value,
+	 or by setting dontUseMesonConfigure. To run these files, you should
+	 accompany meson with ninja. mesonFlags controls only the flags passed
+	 to meson. By default, parallel building is enabled as Meson supports
+	 parallel building almost everywhere.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      ninja
+     </term>
+     <listitem>
+       <para>
+	 Overrides the build, install, and check phase to run ninja instead of
+	 make. You can disable this behavior with the dontUseNinjaBuild,
+	 dontUseNinjaInstall, and dontUseNinjaCheck, respectively. Parallel
+	 building is enabled by default in Ninja.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      unzip
+     </term>
+     <listitem>
+       <para>
+	 This setup hook will allow you to unzip .zip files specified in $src.
+	 There are many similar packages like unrar, undmg, etc.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      wafHook
+     </term>
+     <listitem>
+       <para>
+	 Overrides the configure, build, and install phases. This will run the
+	 "waf" script used by many projects. If waf doesn’t exist, it will copy
+	 the version of waf available in Nixpkgs wafFlags can be used to pass
+	 flags to the waf script.
+      </para>
+     </listitem>
+    </varlistentry>
+    <varlistentry>
+     <term>
+      scons
+     </term>
+     <listitem>
+       <para>
+	 Overrides the build, install, and check phases. This uses the scons
+	 build system as a replacement for make. scons does not provide a
+	 configure phase, so everything is managed at build and install time.
+      </para>
+     </listitem>
+    </varlistentry>
+  </variablelist>
+  </para>
+ </section>
+ <section xml:id="sec-purity-in-nixpkgs">
+  <title>Purity in Nixpkgs</title>
+
+  <para>
+   [measures taken to prevent dependencies on packages outside the store, and
+   what you can do to prevent them]
+  </para>
+
+  <para>
+   GCC doesn't search in locations such as <filename>/usr/include</filename>.
+   In fact, attempts to add such directories through the <option>-I</option>
+   flag are filtered out. Likewise, the linker (from GNU binutils) doesn't
+   search in standard locations such as <filename>/usr/lib</filename>. Programs
+   built on Linux are linked against a GNU C Library that likewise doesn't
+   search in the default system locations.
+  </para>
+ </section>
+ <section xml:id="sec-hardening-in-nixpkgs">
+  <title>Hardening in Nixpkgs</title>
+
+  <para>
+   There are flags available to harden packages at compile or link-time. These
+   can be toggled using the <varname>stdenv.mkDerivation</varname> parameters
+   <varname>hardeningDisable</varname> and <varname>hardeningEnable</varname>.
+  </para>
+
+  <para>
+   Both parameters take a list of flags as strings. The special
+   <varname>"all"</varname> flag can be passed to
+   <varname>hardeningDisable</varname> to turn off all hardening. These flags
+   can also be used as environment variables for testing or development
+   purposes.
+  </para>
+
+  <para>
+   The following flags are enabled by default and might require disabling with
+   <varname>hardeningDisable</varname> if the program to package is
+   incompatible.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>format</varname>
+    </term>
+    <listitem>
+     <para>
+      Adds the <option>-Wformat -Wformat-security
+      -Werror=format-security</option> compiler options. At present, this warns
+      about calls to <varname>printf</varname> and <varname>scanf</varname>
+      functions where the format string is not a string literal and there are
+      no format arguments, as in <literal>printf(foo);</literal>. This may be a
+      security hole if the format string came from untrusted input and contains
+      <literal>%n</literal>.
+     </para>
+     <para>
+      This needs to be turned off or fixed for errors similar to:
+     </para>
+<programlisting>
+/tmp/nix-build-zynaddsubfx-2.5.2.drv-0/zynaddsubfx-2.5.2/src/UI/guimain.cpp:571:28: error: format not a string literal and no format arguments [-Werror=format-security]
+         printf(help_message);
+                            ^
+cc1plus: some warnings being treated as errors
+    </programlisting>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>stackprotector</varname>
+    </term>
+    <listitem>
+     <para>
+      Adds the <option>-fstack-protector-strong --param
+      ssp-buffer-size=4</option> compiler options. This adds safety checks
+      against stack overwrites rendering many potential code injection attacks
+      into aborting situations. In the best case this turns code injection
+      vulnerabilities into denial of service or into non-issues (depending on
+      the application).
+     </para>
+     <para>
+      This needs to be turned off or fixed for errors similar to:
+     </para>
+<programlisting>
+bin/blib.a(bios_console.o): In function `bios_handle_cup':
+/tmp/nix-build-ipxe-20141124-5cbdc41.drv-0/ipxe-5cbdc41/src/arch/i386/firmware/pcbios/bios_console.c:86: undefined reference to `__stack_chk_fail'
+    </programlisting>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>fortify</varname>
+    </term>
+    <listitem>
+     <para>
+      Adds the <option>-O2 -D_FORTIFY_SOURCE=2</option> compiler options.
+      During code generation the compiler knows a great deal of information
+      about buffer sizes (where possible), and attempts to replace insecure
+      unlimited length buffer function calls with length-limited ones. This is
+      especially useful for old, crufty code. Additionally, format strings in
+      writable memory that contain '%n' are blocked. If an application depends
+      on such a format string, it will need to be worked around.
+     </para>
+     <para>
+      Additionally, some warnings are enabled which might trigger build
+      failures if compiler warnings are treated as errors in the package build.
+      In this case, set <option>NIX_CFLAGS_COMPILE</option> to
+      <option>-Wno-error=warning-type</option>.
+     </para>
+     <para>
+      This needs to be turned off or fixed for errors similar to:
+     </para>
+<programlisting>
+malloc.c:404:15: error: return type is an incomplete type
+malloc.c:410:19: error: storage size of 'ms' isn't known
+    </programlisting>
+<programlisting>
+strdup.h:22:1: error: expected identifier or '(' before '__extension__'
+    </programlisting>
+<programlisting>
+strsep.c:65:23: error: register name not specified for 'delim'
+    </programlisting>
+<programlisting>
+installwatch.c:3751:5: error: conflicting types for '__open_2'
+    </programlisting>
+<programlisting>
+fcntl2.h:50:4: error: call to '__open_missing_mode' declared with attribute error: open with O_CREAT or O_TMPFILE in second argument needs 3 arguments
+    </programlisting>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>pic</varname>
+    </term>
+    <listitem>
+     <para>
+      Adds the <option>-fPIC</option> compiler options. This options adds
+      support for position independent code in shared libraries and thus making
+      ASLR possible.
+     </para>
+     <para>
+      Most notably, the Linux kernel, kernel modules and other code not running
+      in an operating system environment like boot loaders won't build with PIC
+      enabled. The compiler will is most cases complain that PIC is not
+      supported for a specific build.
+     </para>
+     <para>
+      This needs to be turned off or fixed for assembler errors similar to:
+     </para>
+<programlisting>
+ccbLfRgg.s: Assembler messages:
+ccbLfRgg.s:33: Error: missing or invalid displacement expression `private_key_len@GOTOFF'
+    </programlisting>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>strictoverflow</varname>
+    </term>
+    <listitem>
+     <para>
+      Signed integer overflow is undefined behaviour according to the C
+      standard. If it happens, it is an error in the program as it should check
+      for overflow before it can happen, not afterwards. GCC provides built-in
+      functions to perform arithmetic with overflow checking, which are correct
+      and faster than any custom implementation. As a workaround, the option
+      <option>-fno-strict-overflow</option> makes gcc behave as if signed
+      integer overflows were defined.
+     </para>
+     <para>
+      This flag should not trigger any build or runtime errors.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>relro</varname>
+    </term>
+    <listitem>
+     <para>
+      Adds the <option>-z relro</option> linker option. During program load,
+      several ELF memory sections need to be written to by the linker, but can
+      be turned read-only before turning over control to the program. This
+      prevents some GOT (and .dtors) overwrite attacks, but at least the part
+      of the GOT used by the dynamic linker (.got.plt) is still vulnerable.
+     </para>
+     <para>
+      This flag can break dynamic shared object loading. For instance, the
+      module systems of Xorg and OpenCV are incompatible with this flag. In
+      almost all cases the <varname>bindnow</varname> flag must also be
+      disabled and incompatible programs typically fail with similar errors at
+      runtime.
+     </para>
+    </listitem>
+   </varlistentry>
+   <varlistentry>
+    <term>
+     <varname>bindnow</varname>
+    </term>
+    <listitem>
+     <para>
+      Adds the <option>-z bindnow</option> linker option. During program load,
+      all dynamic symbols are resolved, allowing for the complete GOT to be
+      marked read-only (due to <varname>relro</varname>). This prevents GOT
+      overwrite attacks. For very large applications, this can incur some
+      performance loss during initial load while symbols are resolved, but this
+      shouldn't be an issue for daemons.
+     </para>
+     <para>
+      This flag can break dynamic shared object loading. For instance, the
+      module systems of Xorg and PHP are incompatible with this flag. Programs
+      incompatible with this flag often fail at runtime due to missing symbols,
+      like:
+     </para>
+<programlisting>
+intel_drv.so: undefined symbol: vgaHWFreeHWRec
+    </programlisting>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <para>
+   The following flags are disabled by default and should be enabled with
+   <varname>hardeningEnable</varname> for packages that take untrusted input
+   like network services.
+  </para>
+
+  <variablelist>
+   <varlistentry>
+    <term>
+     <varname>pie</varname>
+    </term>
+    <listitem>
+     <para>
+      Adds the <option>-fPIE</option> compiler and <option>-pie</option> linker
+      options. Position Independent Executables are needed to take advantage of
+      Address Space Layout Randomization, supported by modern kernel versions.
+      While ASLR can already be enforced for data areas in the stack and heap
+      (brk and mmap), the code areas must be compiled as position-independent.
+      Shared libraries already do this with the <varname>pic</varname> flag, so
+      they gain ASLR automatically, but binary .text regions need to be build
+      with <varname>pie</varname> to gain ASLR. When this happens, ROP attacks
+      are much harder since there are no static locations to bounce off of
+      during a memory corruption attack.
+     </para>
+    </listitem>
+   </varlistentry>
+  </variablelist>
+
+  <para>
+   For more in-depth information on these hardening flags and hardening in
+   general, refer to the
+   <link xlink:href="https://wiki.debian.org/Hardening">Debian Wiki</link>,
+   <link xlink:href="https://wiki.ubuntu.com/Security/Features">Ubuntu
+   Wiki</link>,
+   <link xlink:href="https://wiki.gentoo.org/wiki/Project:Hardened">Gentoo
+   Wiki</link>, and the
+   <link xlink:href="https://wiki.archlinux.org/index.php/DeveloperWiki:Security">
+   Arch Wiki</link>.
+  </para>
+ </section>
+</chapter>
diff --git a/nixpkgs/doc/style.css b/nixpkgs/doc/style.css
new file mode 100644
index 000000000000..0db907815b6b
--- /dev/null
+++ b/nixpkgs/doc/style.css
@@ -0,0 +1,271 @@
+/* Copied from http://bakefile.sourceforge.net/, which appears
+   licensed under the GNU GPL. */
+
+
+/***************************************************************************
+                             Basic headers and text:
+ ***************************************************************************/
+
+body
+{
+    font-family: "Nimbus Sans L", sans-serif;
+    background: white;
+    margin: 2em 1em 2em 1em;
+}
+
+h1, h2, h3, h4
+{
+    color: #005aa0;
+}
+
+h1 /* title */
+{
+    font-size: 200%;
+}
+
+h2 /* chapters, appendices, subtitle */
+{
+    font-size: 180%;
+}
+
+/* Extra space between chapters, appendices. */
+div.chapter > div.titlepage h2, div.appendix > div.titlepage h2
+{
+    margin-top: 1.5em;
+}
+
+div.section > div.titlepage h2 /* sections */
+{
+    font-size: 150%;
+    margin-top: 1.5em;
+}
+
+h3 /* subsections */
+{
+    font-size: 125%;
+}
+
+div.simplesect h2
+{
+    font-size: 110%;
+}
+
+div.appendix h3
+{
+    font-size: 150%;
+    margin-top: 1.5em;
+}
+
+div.refnamediv h2, div.refsynopsisdiv h2, div.refsection h2 /* refentry parts */
+{
+    margin-top: 1.4em;
+    font-size: 125%;
+}
+
+div.refsection h3
+{
+    font-size: 110%;
+}
+
+
+/***************************************************************************
+                               Examples:
+ ***************************************************************************/
+
+div.example
+{
+    border: 1px solid #b0b0b0;
+    padding: 6px 6px;
+    margin-left: 1.5em;
+    margin-right: 1.5em;
+    background: #f4f4f8;
+    border-radius: 0.4em;
+    box-shadow: 0.4em 0.4em 0.5em #e0e0e0;
+}
+
+div.example p.title
+{
+    margin-top: 0em;
+}
+
+div.example pre
+{
+    box-shadow: none;
+}
+
+
+/***************************************************************************
+                            Screen dumps:
+ ***************************************************************************/
+
+pre.screen, pre.programlisting
+{
+    border: 1px solid #b0b0b0;
+    padding: 3px 3px;
+    margin-left: 1.5em;
+    margin-right: 1.5em;
+
+    background: #f4f4f8;
+    font-family: monospace;
+    border-radius: 0.4em;
+    box-shadow: 0.4em 0.4em 0.5em #e0e0e0;
+}
+
+div.example pre.programlisting
+{
+    border: 0px;
+    padding: 0 0;
+    margin: 0 0 0 0;
+}
+
+/***************************************************************************
+                               Notes, warnings etc:
+ ***************************************************************************/
+
+.note, .warning
+{
+    border: 1px solid #b0b0b0;
+    padding: 3px 3px;
+    margin-left: 1.5em;
+    margin-right: 1.5em;
+    margin-bottom: 1em;
+    padding: 0.3em 0.3em 0.3em 0.3em;
+    background: #fffff5;
+    border-radius: 0.4em;
+    box-shadow: 0.4em 0.4em 0.5em #e0e0e0;
+}
+
+div.note, div.warning
+{
+    font-style: italic;
+}
+
+div.note h3, div.warning h3
+{
+    color: red;
+    font-size: 100%;
+    padding-right: 0.5em;
+    display: inline;
+}
+
+div.note p, div.warning p
+{
+    margin-bottom: 0em;
+}
+
+div.note h3 + p, div.warning h3 + p
+{
+    display: inline;
+}
+
+div.note h3
+{
+    color: blue;
+    font-size: 100%;
+}
+
+div.navfooter *
+{
+    font-size: 90%;
+}
+
+
+/***************************************************************************
+                        Links colors and highlighting:
+ ***************************************************************************/
+
+a { text-decoration: none; }
+a:hover { text-decoration: underline; }
+a:link { color: #0048b3; }
+a:visited { color: #002a6a; }
+
+
+/***************************************************************************
+                              Table of contents:
+ ***************************************************************************/
+
+div.toc
+{
+    font-size: 90%;
+}
+
+div.toc dl
+{
+    margin-top: 0em;
+    margin-bottom: 0em;
+}
+
+
+/***************************************************************************
+                               Special elements:
+ ***************************************************************************/
+
+tt, code
+{
+    color: #400000;
+}
+
+.term
+{
+    font-weight: bold;
+
+}
+
+div.variablelist dd p, div.glosslist dd p
+{
+    margin-top: 0em;
+}
+
+div.variablelist dd, div.glosslist dd
+{
+    margin-left: 1.5em;
+}
+
+div.glosslist dt
+{
+    font-style: italic;
+}
+
+.varname
+{
+    color: #400000;
+}
+
+span.command strong
+{
+    font-weight: normal;
+    color: #400000;
+}
+
+div.calloutlist table
+{
+    box-shadow: none;
+}
+
+table
+{
+    border-collapse: collapse;
+    box-shadow: 0.4em 0.4em 0.5em #e0e0e0;
+}
+
+table.simplelist
+{
+    text-align: left;
+    color: #005aa0;
+    border: 0;
+    padding: 5px;
+    background: #fffff5;
+    font-weight: normal;
+    font-style: italic;
+    box-shadow: none;
+    margin-bottom: 1em;
+}
+
+div.navheader table, div.navfooter table {
+    box-shadow: none;
+}
+
+div.affiliation
+{
+    font-style: italic;
+}
diff --git a/nixpkgs/doc/submitting-changes.xml b/nixpkgs/doc/submitting-changes.xml
new file mode 100644
index 000000000000..4a6a2c634a58
--- /dev/null
+++ b/nixpkgs/doc/submitting-changes.xml
@@ -0,0 +1,523 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-submitting-changes">
+ <title>Submitting changes</title>
+ <section xml:id="submitting-changes-making-patches">
+  <title>Making patches</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Read <link xlink:href="https://nixos.org/nixpkgs/manual/">Manual (How to
+     write packages for Nix)</link>.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Fork the repository on GitHub.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Create a branch for your future fix.
+     <itemizedlist>
+      <listitem>
+       <para>
+        You can make branch from a commit of your local
+        <command>nixos-version</command>. That will help you to avoid
+        additional local compilations. Because you will receive packages from
+        binary cache.
+        <itemizedlist>
+         <listitem>
+          <para>
+           For example: <command>nixos-version</command> returns
+           <command>15.05.git.0998212 (Dingo)</command>. So you can do:
+          </para>
+         </listitem>
+        </itemizedlist>
+<screen>
+$ git checkout 0998212
+$ git checkout -b 'fix/pkg-name-update'
+</screen>
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Please avoid working directly on the <command>master</command> branch.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Make commits of logical units.
+     <itemizedlist>
+      <listitem>
+       <para>
+        If you removed pkgs, made some major NixOS changes etc., write about
+        them in
+        <command>nixos/doc/manual/release-notes/rl-unstable.xml</command>.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Check for unnecessary whitespace with <command>git diff --check</command>
+     before committing.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Format the commit in a following way:
+    </para>
+<programlisting>
+(pkg-name | nixos/&lt;module>): (from -> to | init at version | refactor | etc)
+Additional information.
+</programlisting>
+    <itemizedlist>
+     <listitem>
+      <para>
+       Examples:
+       <itemizedlist>
+        <listitem>
+         <para>
+          <command>nginx: init at 2.0.1</command>
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          <command>firefox: 54.0.1 -> 55.0</command>
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          <command>nixos/hydra: add bazBaz option</command>
+         </para>
+        </listitem>
+        <listitem>
+         <para>
+          <command>nixos/nginx: refactor config generation</command>
+         </para>
+        </listitem>
+       </itemizedlist>
+      </para>
+     </listitem>
+    </itemizedlist>
+   </listitem>
+   <listitem>
+    <para>
+     Test your changes. If you work with
+     <itemizedlist>
+      <listitem>
+       <para>
+        nixpkgs:
+        <itemizedlist>
+         <listitem>
+          <para>
+           update pkg ->
+           <itemizedlist>
+            <listitem>
+             <para>
+              <command>nix-env -i pkg-name -f &lt;path to your local nixpkgs
+              folder&gt;</command>
+             </para>
+            </listitem>
+           </itemizedlist>
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           add pkg ->
+           <itemizedlist>
+            <listitem>
+             <para>
+              Make sure it's in
+              <command>pkgs/top-level/all-packages.nix</command>
+             </para>
+            </listitem>
+            <listitem>
+             <para>
+              <command>nix-env -i pkg-name -f &lt;path to your local nixpkgs
+              folder&gt;</command>
+             </para>
+            </listitem>
+           </itemizedlist>
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           <emphasis>If you don't want to install pkg in you
+           profile</emphasis>.
+           <itemizedlist>
+            <listitem>
+             <para>
+              <command>nix-build -A pkg-attribute-name &lt;path to your local
+              nixpkgs folder&gt;/default.nix</command> and check results in the
+              folder <command>result</command>. It will appear in the same
+              directory where you did <command>nix-build</command>.
+             </para>
+            </listitem>
+           </itemizedlist>
+          </para>
+         </listitem>
+         <listitem>
+          <para>
+           If you did <command>nix-env -i pkg-name</command> you can do
+           <command>nix-env -e pkg-name</command> to uninstall it from your
+           system.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        NixOS and its modules:
+        <itemizedlist>
+         <listitem>
+          <para>
+           You can add new module to your NixOS configuration file (usually
+           it's <command>/etc/nixos/configuration.nix</command>). And do
+           <command>sudo nixos-rebuild test -I nixpkgs=&lt;path to your local
+           nixpkgs folder&gt; --fast</command>.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     If you have commits <command>pkg-name: oh, forgot to insert
+     whitespace</command>: squash commits in this case. Use <command>git rebase
+     -i</command>.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Rebase you branch against current <command>master</command>.
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+ <section xml:id="submitting-changes-submitting-changes">
+  <title>Submitting changes</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Push your changes to your fork of nixpkgs.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Create pull request:
+     <itemizedlist>
+      <listitem>
+       <para>
+        Write the title in format <command>(pkg-name | nixos/&lt;module>):
+        improvement</command>.
+        <itemizedlist>
+         <listitem>
+          <para>
+           If you update the pkg, write versions <command>from -> to</command>.
+          </para>
+         </listitem>
+        </itemizedlist>
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Write in comment if you have tested your patch. Do not rely much on
+        <command>TravisCI</command>.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        If you make an improvement, write about your motivation.
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        Notify maintainers of the package. For example add to the message:
+        <command>cc @jagajaga @domenkozar</command>.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+ <section xml:id="submitting-changes-pull-request-template">
+  <title>Pull Request Template</title>
+
+  <para>
+   The pull request template helps determine what steps have been made for a
+   contribution so far, and will help guide maintainers on the status of a
+   change. The motivation section of the PR should include any extra details
+   the title does not address and link any existing issues related to the pull
+   request.
+  </para>
+
+  <para>
+   When a PR is created, it will be pre-populated with some checkboxes detailed
+   below:
+  </para>
+
+  <section xml:id="submitting-changes-tested-with-sandbox">
+   <title>Tested using sandboxing</title>
+
+   <para>
+    When sandbox builds are enabled, Nix will setup an isolated environment for
+    each build process. It is used to remove further hidden dependencies set by
+    the build environment to improve reproducibility. This includes access to
+    the network during the build outside of <function>fetch*</function>
+    functions and files outside the Nix store. Depending on the operating
+    system access to other resources are blocked as well (ex. inter process
+    communication is isolated on Linux); see
+    <link
+      xlink:href="https://nixos.org/nix/manual/#description-45">build-use-sandbox</link>
+    in Nix manual for details.
+   </para>
+
+   <para>
+    Sandboxing is not enabled by default in Nix due to a small performance hit
+    on each build. In pull requests for
+    <link
+        xlink:href="https://github.com/NixOS/nixpkgs/">nixpkgs</link>
+    people are asked to test builds with sandboxing enabled (see
+    <literal>Tested using sandboxing</literal> in the pull request template)
+    because
+    in<link
+        xlink:href="https://nixos.org/hydra/">https://nixos.org/hydra/</link>
+    sandboxing is also used.
+   </para>
+
+   <para>
+    Depending if you use NixOS or other platforms you can use one of the
+    following methods to enable sandboxing
+    <emphasis role="bold">before</emphasis> building the package:
+    <itemizedlist>
+     <listitem>
+      <para>
+       <emphasis role="bold">Globally enable sandboxing on NixOS</emphasis>:
+       add the following to <filename>configuration.nix</filename>
+<screen>nix.useSandbox = true;</screen>
+      </para>
+     </listitem>
+     <listitem>
+      <para>
+       <emphasis role="bold">Globally enable sandboxing on non-NixOS
+       platforms</emphasis>: add the following to:
+       <filename>/etc/nix/nix.conf</filename>
+<screen>build-use-sandbox = true</screen>
+      </para>
+     </listitem>
+    </itemizedlist>
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-platform-diversity">
+   <title>Built on platform(s)</title>
+
+   <para>
+    Many Nix packages are designed to run on multiple platforms. As such, it's
+    important to let the maintainer know which platforms your changes have been
+    tested on. It's not always practical to test a change on all platforms, and
+    is not required for a pull request to be merged. Only check the systems you
+    tested the build on in this section.
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-nixos-tests">
+   <title>Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)</title>
+
+   <para>
+    Packages with automated tests are much more likely to be merged in a timely
+    fashion because it doesn't require as much manual testing by the maintainer
+    to verify the functionality of the package. If there are existing tests for
+    the package, they should be run to verify your changes do not break the
+    tests. Tests only apply to packages with NixOS modules defined and can only
+    be run on Linux. For more details on writing and running tests, see the
+    <link
+        xlink:href="https://nixos.org/nixos/manual/index.html#sec-nixos-tests">section
+    in the NixOS manual</link>.
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-tested-compilation">
+   <title>Tested compilation of all pkgs that depend on this change using <command>nox-review</command></title>
+
+   <para>
+    If you are updating a package's version, you can use nox to make sure all
+    packages that depend on the updated package still compile correctly. This
+    can be done using the nox utility. The <command>nox-review</command>
+    utility can look for and build all dependencies either based on uncommited
+    changes with the <literal>wip</literal> option or specifying a github pull
+    request number.
+   </para>
+
+   <para>
+    review uncommitted changes:
+<screen>nix-shell -p nox --run "nox-review wip"</screen>
+   </para>
+
+   <para>
+    review changes from pull request number 12345:
+<screen>nix-shell -p nox --run "nox-review pr 12345"</screen>
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-tested-execution">
+   <title>Tested execution of all binary files (usually in <filename>./result/bin/</filename>)</title>
+
+   <para>
+    It's important to test any executables generated by a build when you change
+    or create a package in nixpkgs. This can be done by looking in
+    <filename>./result/bin</filename> and running any files in there, or at a
+    minimum, the main executable for the package. For example, if you make a
+    change to <package>texlive</package>, you probably would only check the
+    binaries associated with the change you made rather than testing all of
+    them.
+   </para>
+  </section>
+
+  <section xml:id="submitting-changes-contribution-standards">
+   <title>Meets Nixpkgs contribution standards</title>
+
+   <para>
+    The last checkbox is fits
+    <link
+        xlink:href="https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md">CONTRIBUTING.md</link>.
+    The contributing document has detailed information on standards the Nix
+    community has for commit messages, reviews, licensing of contributions you
+    make to the project, etc... Everyone should read and understand the
+    standards the community has for contributing before submitting a pull
+    request.
+   </para>
+  </section>
+ </section>
+ <section xml:id="submitting-changes-hotfixing-pull-requests">
+  <title>Hotfixing pull requests</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Make the appropriate changes in you branch.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Don't create additional commits, do
+     <itemizedlist>
+      <listitem>
+       <para>
+        <command>git rebase -i</command>
+       </para>
+      </listitem>
+      <listitem>
+       <para>
+        <command>git push --force</command> to your branch.
+       </para>
+      </listitem>
+     </itemizedlist>
+    </para>
+   </listitem>
+  </itemizedlist>
+ </section>
+ <section xml:id="submitting-changes-commit-policy">
+  <title>Commit policy</title>
+
+  <itemizedlist>
+   <listitem>
+    <para>
+     Commits must be sufficiently tested before being merged, both for the
+     master and staging branches.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     Hydra builds for master and staging should not be used as testing
+     platform, it's a build farm for changes that have been already tested.
+    </para>
+   </listitem>
+   <listitem>
+    <para>
+     When changing the bootloader installation process, extra care must be
+     taken. Grub installations cannot be rolled back, hence changes may break
+     people's installations forever. For any non-trivial change to the
+     bootloader please file a PR asking for review, especially from @edolstra.
+    </para>
+   </listitem>
+  </itemizedlist>
+
+  <section xml:id="submitting-changes-master-branch">
+   <title>Master branch</title>
+
+   <itemizedlist>
+    <listitem>
+     <para>
+      It should only see non-breaking commits that do not cause mass rebuilds.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </section>
+
+  <section xml:id="submitting-changes-staging-branch">
+   <title>Staging branch</title>
+
+   <itemizedlist>
+    <listitem>
+     <para>
+      It's only for non-breaking mass-rebuild commits. That means it's not to
+      be used for testing, and changes must have been well tested already.
+      <link xlink:href="https://web.archive.org/web/20160528180406/http://comments.gmane.org/gmane.linux.distributions.nixos/13447">Read
+      policy here</link>.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+      If the branch is already in a broken state, please refrain from adding
+      extra new breakages. Stabilize it for a few days, merge into master, then
+      resume development on staging.
+      <link xlink:href="http://hydra.nixos.org/jobset/nixpkgs/staging#tabs-evaluations">Keep
+      an eye on the staging evaluations here</link>. If any fixes for staging
+      happen to be already in master, then master can be merged into staging.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </section>
+
+  <section xml:id="submitting-changes-stable-release-branches">
+   <title>Stable release branches</title>
+
+   <itemizedlist>
+    <listitem>
+     <para>
+      If you're cherry-picking a commit to a stable release branch, always use
+      <command>git cherry-pick -xe</command> and ensure the message contains a
+      clear description about why this needs to be included in the stable
+      branch.
+     </para>
+     <para>
+      An example of a cherry-picked commit would look like this:
+     </para>
+<screen>
+nixos: Refactor the world.
+
+The original commit message describing the reason why the world was torn apart.
+
+(cherry picked from commit abcdef)
+Reason: I just had a gut feeling that this would also be wanted by people from
+the stone age.
+      </screen>
+    </listitem>
+   </itemizedlist>
+  </section>
+ </section>
+</chapter>