WIP: broken merge but need a git checkpoint

47 files changed, 1387 insertions, 818 deletions

diff --git a/doc/manual/anchors.jq b/doc/manual/anchors.jq
new file mode 100755
index 000000000..72309779c
--- /dev/null
+++ b/doc/manual/anchors.jq
@@ -0,0 +1,31 @@
+"\\[\\]\\{#(?<anchor>[^\\}]+?)\\}" as $empty_anchor_regex |
+"\\[(?<text>[^\\]]+?)\\]\\{#(?<anchor>[^\\}]+?)\\}" as $anchor_regex |
+
+
+def transform_anchors_html:
+    . | gsub($empty_anchor_regex; "<a name=\"" + .anchor + "\"></a>")
+      | gsub($anchor_regex; "<a href=\"#" + .anchor + "\" id=\"" + .anchor + "\">" + .text + "</a>");
+
+
+def transform_anchors_strip:
+    . | gsub($empty_anchor_regex; "")
+      | gsub($anchor_regex; .text);
+
+
+def map_contents_recursively(transformer):
+    . + {
+        Chapter: (.Chapter + {
+            content: .Chapter.content | transformer,
+            sub_items: .Chapter.sub_items | map(map_contents_recursively(transformer)),
+        }),
+    };
+
+
+def process_command:
+    .[0] as $context |
+    .[1] as $body |
+    $body + {
+        sections: $body.sections | map(map_contents_recursively(if $context.renderer == "html" then transform_anchors_html else transform_anchors_strip end)),
+    };
+
+process_command
diff --git a/doc/manual/book.toml b/doc/manual/book.toml
index fee41dfb3..5f78a7614 100644
--- a/doc/manual/book.toml
+++ b/doc/manual/book.toml
@@ -1,2 +1,7 @@
 [output.html]
 additional-css = ["custom.css"]
+additional-js = ["redirects.js"]
+
+[preprocessor.anchors]
+renderers = ["html"]
+command = "jq --from-file doc/manual/anchors.jq"
diff --git a/doc/manual/generate-manpage.nix b/doc/manual/generate-manpage.nix
index 244cfa0c2..17701c3a3 100644
--- a/doc/manual/generate-manpage.nix
+++ b/doc/manual/generate-manpage.nix
@@ -1,4 +1,4 @@
-{ command, renderLinks ? false }:
+{ command }:
 
 with builtins;
 with import ./utils.nix;
@@ -21,9 +21,7 @@ let
            listCommands = cmds:
              concatStrings (map (name:
                "* "
-               + (if renderLinks
-                  then "[`${command} ${name}`](./${appendName filename name}.md)"
-                  else "`${command} ${name}`")
+               + "[`${command} ${name}`](./${appendName filename name}.md)"
                + " - ${cmds.${name}.description}\n")
                (attrNames cmds));
          in
diff --git a/doc/manual/local.mk b/doc/manual/local.mk
index c1ce8aaeb..364e02967 100644
--- a/doc/manual/local.mk
+++ b/doc/manual/local.mk
@@ -1,5 +1,9 @@
 ifeq ($(doc_generate),yes)
 
+MANUAL_SRCS := \
+  $(call rwildcard, $(d)/src, *.md) \
+  $(call rwildcard, $(d)/src, */*.md)
+
 # Generate man pages.
 man-pages := $(foreach n, \
   nix-env.1 nix-build.1 nix-shell.1 nix-store.1 nix-instantiate.1 \
@@ -46,7 +50,7 @@ $(d)/src/SUMMARY.md: $(d)/src/SUMMARY.md.in $(d)/src/command-ref/new-cli
 
 $(d)/src/command-ref/new-cli: $(d)/nix.json $(d)/generate-manpage.nix $(bindir)/nix
 	@rm -rf $@
-	$(trace-gen) $(nix-eval) --write-to $@ --expr 'import doc/manual/generate-manpage.nix { command = builtins.readFile $<; renderLinks = true; }'
+	$(trace-gen) $(nix-eval) --write-to $@ --expr 'import doc/manual/generate-manpage.nix { command = builtins.readFile $<; }'
 
 $(d)/src/command-ref/conf-file.md: $(d)/conf-file.json $(d)/generate-options.nix $(d)/src/command-ref/conf-file-prefix.md $(bindir)/nix
 	@cat doc/manual/src/command-ref/conf-file-prefix.md > $@.tmp
@@ -61,10 +65,10 @@ $(d)/conf-file.json: $(bindir)/nix
 	$(trace-gen) $(dummy-env) $(bindir)/nix show-config --json --experimental-features nix-command > $@.tmp
 	@mv $@.tmp $@
 
-$(d)/src/expressions/builtins.md: $(d)/builtins.json $(d)/generate-builtins.nix $(d)/src/expressions/builtins-prefix.md $(bindir)/nix
-	@cat doc/manual/src/expressions/builtins-prefix.md > $@.tmp
+$(d)/src/language/builtins.md: $(d)/builtins.json $(d)/generate-builtins.nix $(d)/src/language/builtins-prefix.md $(bindir)/nix
+	@cat doc/manual/src/language/builtins-prefix.md > $@.tmp
 	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-builtins.nix (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp
-	@cat doc/manual/src/expressions/builtins-suffix.md >> $@.tmp
+	@cat doc/manual/src/language/builtins-suffix.md >> $@.tmp
 	@mv $@.tmp $@
 
 $(d)/builtins.json: $(bindir)/nix
@@ -92,12 +96,12 @@ doc/manual/generated/man1/nix3-manpages: $(d)/src/command-ref/new-cli
 	  if [[ $$name = SUMMARY ]]; then continue; fi; \
 	  printf "Title: %s\n\n" "$$name" > $$tmpFile; \
 	  cat $$i >> $$tmpFile; \
-	  lowdown -sT man -M section=1 $$tmpFile -o $(DESTDIR)$$(dirname $@)/$$name.1; \
+	  lowdown -sT man --nroff-nolinks -M section=1 $$tmpFile -o $(DESTDIR)$$(dirname $@)/$$name.1; \
 	  rm $$tmpFile; \
 	done
 	@touch $@
 
-$(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/custom.css $(d)/src/SUMMARY.md $(d)/src/command-ref/new-cli $(d)/src/command-ref/conf-file.md $(d)/src/expressions/builtins.md $(call rwildcard, $(d)/src, *.md)
+$(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/anchors.jq $(d)/custom.css $(d)/src/SUMMARY.md $(d)/src/command-ref/new-cli $(d)/src/command-ref/conf-file.md $(d)/src/language/builtins.md
 	$(trace-gen) RUST_LOG=warn mdbook build doc/manual -d $(DESTDIR)$(docdir)/manual
 
 endif
diff --git a/doc/manual/redirects.js b/doc/manual/redirects.js
new file mode 100644
index 000000000..167e221b8
--- /dev/null
+++ b/doc/manual/redirects.js
@@ -0,0 +1,330 @@
+// Redirects from old DocBook manual.
+var redirects = {
+  "#part-advanced-topics": "advanced-topics/advanced-topics.html",
+  "#chap-tuning-cores-and-jobs": "advanced-topics/cores-vs-jobs.html",
+  "#chap-diff-hook": "advanced-topics/diff-hook.html",
+  "#check-dirs-are-unregistered": "advanced-topics/diff-hook.html#check-dirs-are-unregistered",
+  "#chap-distributed-builds": "advanced-topics/distributed-builds.html",
+  "#chap-post-build-hook": "advanced-topics/post-build-hook.html",
+  "#chap-post-build-hook-caveats": "advanced-topics/post-build-hook.html#implementation-caveats",
+  "#part-command-ref": "command-ref/command-ref.html",
+  "#conf-allow-import-from-derivation": "command-ref/conf-file.html#conf-allow-import-from-derivation",
+  "#conf-allow-new-privileges": "command-ref/conf-file.html#conf-allow-new-privileges",
+  "#conf-allowed-uris": "command-ref/conf-file.html#conf-allowed-uris",
+  "#conf-allowed-users": "command-ref/conf-file.html#conf-allowed-users",
+  "#conf-auto-optimise-store": "command-ref/conf-file.html#conf-auto-optimise-store",
+  "#conf-binary-cache-public-keys": "command-ref/conf-file.html#conf-binary-cache-public-keys",
+  "#conf-binary-caches": "command-ref/conf-file.html#conf-binary-caches",
+  "#conf-build-compress-log": "command-ref/conf-file.html#conf-build-compress-log",
+  "#conf-build-cores": "command-ref/conf-file.html#conf-build-cores",
+  "#conf-build-extra-chroot-dirs": "command-ref/conf-file.html#conf-build-extra-chroot-dirs",
+  "#conf-build-extra-sandbox-paths": "command-ref/conf-file.html#conf-build-extra-sandbox-paths",
+  "#conf-build-fallback": "command-ref/conf-file.html#conf-build-fallback",
+  "#conf-build-max-jobs": "command-ref/conf-file.html#conf-build-max-jobs",
+  "#conf-build-max-log-size": "command-ref/conf-file.html#conf-build-max-log-size",
+  "#conf-build-max-silent-time": "command-ref/conf-file.html#conf-build-max-silent-time",
+  "#conf-build-repeat": "command-ref/conf-file.html#conf-build-repeat",
+  "#conf-build-timeout": "command-ref/conf-file.html#conf-build-timeout",
+  "#conf-build-use-chroot": "command-ref/conf-file.html#conf-build-use-chroot",
+  "#conf-build-use-sandbox": "command-ref/conf-file.html#conf-build-use-sandbox",
+  "#conf-build-use-substitutes": "command-ref/conf-file.html#conf-build-use-substitutes",
+  "#conf-build-users-group": "command-ref/conf-file.html#conf-build-users-group",
+  "#conf-builders": "command-ref/conf-file.html#conf-builders",
+  "#conf-builders-use-substitutes": "command-ref/conf-file.html#conf-builders-use-substitutes",
+  "#conf-compress-build-log": "command-ref/conf-file.html#conf-compress-build-log",
+  "#conf-connect-timeout": "command-ref/conf-file.html#conf-connect-timeout",
+  "#conf-cores": "command-ref/conf-file.html#conf-cores",
+  "#conf-diff-hook": "command-ref/conf-file.html#conf-diff-hook",
+  "#conf-enforce-determinism": "command-ref/conf-file.html#conf-enforce-determinism",
+  "#conf-env-keep-derivations": "command-ref/conf-file.html#conf-env-keep-derivations",
+  "#conf-extra-binary-caches": "command-ref/conf-file.html#conf-extra-binary-caches",
+  "#conf-extra-platforms": "command-ref/conf-file.html#conf-extra-platforms",
+  "#conf-extra-sandbox-paths": "command-ref/conf-file.html#conf-extra-sandbox-paths",
+  "#conf-extra-substituters": "command-ref/conf-file.html#conf-extra-substituters",
+  "#conf-fallback": "command-ref/conf-file.html#conf-fallback",
+  "#conf-fsync-metadata": "command-ref/conf-file.html#conf-fsync-metadata",
+  "#conf-gc-keep-derivations": "command-ref/conf-file.html#conf-gc-keep-derivations",
+  "#conf-gc-keep-outputs": "command-ref/conf-file.html#conf-gc-keep-outputs",
+  "#conf-hashed-mirrors": "command-ref/conf-file.html#conf-hashed-mirrors",
+  "#conf-http-connections": "command-ref/conf-file.html#conf-http-connections",
+  "#conf-keep-build-log": "command-ref/conf-file.html#conf-keep-build-log",
+  "#conf-keep-derivations": "command-ref/conf-file.html#conf-keep-derivations",
+  "#conf-keep-env-derivations": "command-ref/conf-file.html#conf-keep-env-derivations",
+  "#conf-keep-outputs": "command-ref/conf-file.html#conf-keep-outputs",
+  "#conf-max-build-log-size": "command-ref/conf-file.html#conf-max-build-log-size",
+  "#conf-max-free": "command-ref/conf-file.html#conf-max-free",
+  "#conf-max-jobs": "command-ref/conf-file.html#conf-max-jobs",
+  "#conf-max-silent-time": "command-ref/conf-file.html#conf-max-silent-time",
+  "#conf-min-free": "command-ref/conf-file.html#conf-min-free",
+  "#conf-narinfo-cache-negative-ttl": "command-ref/conf-file.html#conf-narinfo-cache-negative-ttl",
+  "#conf-narinfo-cache-positive-ttl": "command-ref/conf-file.html#conf-narinfo-cache-positive-ttl",
+  "#conf-netrc-file": "command-ref/conf-file.html#conf-netrc-file",
+  "#conf-plugin-files": "command-ref/conf-file.html#conf-plugin-files",
+  "#conf-post-build-hook": "command-ref/conf-file.html#conf-post-build-hook",
+  "#conf-pre-build-hook": "command-ref/conf-file.html#conf-pre-build-hook",
+  "#conf-repeat": "command-ref/conf-file.html#conf-repeat",
+  "#conf-require-sigs": "command-ref/conf-file.html#conf-require-sigs",
+  "#conf-restrict-eval": "command-ref/conf-file.html#conf-restrict-eval",
+  "#conf-run-diff-hook": "command-ref/conf-file.html#conf-run-diff-hook",
+  "#conf-sandbox": "command-ref/conf-file.html#conf-sandbox",
+  "#conf-sandbox-dev-shm-size": "command-ref/conf-file.html#conf-sandbox-dev-shm-size",
+  "#conf-sandbox-paths": "command-ref/conf-file.html#conf-sandbox-paths",
+  "#conf-secret-key-files": "command-ref/conf-file.html#conf-secret-key-files",
+  "#conf-show-trace": "command-ref/conf-file.html#conf-show-trace",
+  "#conf-stalled-download-timeout": "command-ref/conf-file.html#conf-stalled-download-timeout",
+  "#conf-substitute": "command-ref/conf-file.html#conf-substitute",
+  "#conf-substituters": "command-ref/conf-file.html#conf-substituters",
+  "#conf-system": "command-ref/conf-file.html#conf-system",
+  "#conf-system-features": "command-ref/conf-file.html#conf-system-features",
+  "#conf-tarball-ttl": "command-ref/conf-file.html#conf-tarball-ttl",
+  "#conf-timeout": "command-ref/conf-file.html#conf-timeout",
+  "#conf-trace-function-calls": "command-ref/conf-file.html#conf-trace-function-calls",
+  "#conf-trusted-binary-caches": "command-ref/conf-file.html#conf-trusted-binary-caches",
+  "#conf-trusted-public-keys": "command-ref/conf-file.html#conf-trusted-public-keys",
+  "#conf-trusted-substituters": "command-ref/conf-file.html#conf-trusted-substituters",
+  "#conf-trusted-users": "command-ref/conf-file.html#conf-trusted-users",
+  "#extra-sandbox-paths": "command-ref/conf-file.html#extra-sandbox-paths",
+  "#sec-conf-file": "command-ref/conf-file.html",
+  "#env-NIX_PATH": "command-ref/env-common.html#env-NIX_PATH",
+  "#env-common": "command-ref/env-common.html",
+  "#envar-remote": "command-ref/env-common.html#env-NIX_REMOTE",
+  "#sec-common-env": "command-ref/env-common.html",
+  "#ch-files": "command-ref/files.html",
+  "#ch-main-commands": "command-ref/main-commands.html",
+  "#opt-out-link": "command-ref/nix-build.html#opt-out-link",
+  "#sec-nix-build": "command-ref/nix-build.html",
+  "#sec-nix-channel": "command-ref/nix-channel.html",
+  "#sec-nix-collect-garbage": "command-ref/nix-collect-garbage.html",
+  "#sec-nix-copy-closure": "command-ref/nix-copy-closure.html",
+  "#sec-nix-daemon": "command-ref/nix-daemon.html",
+  "#refsec-nix-env-install-examples": "command-ref/nix-env.html#examples",
+  "#rsec-nix-env-install": "command-ref/nix-env.html#operation---install",
+  "#rsec-nix-env-set": "command-ref/nix-env.html#operation---set",
+  "#rsec-nix-env-set-flag": "command-ref/nix-env.html#operation---set-flag",
+  "#rsec-nix-env-upgrade": "command-ref/nix-env.html#operation---upgrade",
+  "#sec-nix-env": "command-ref/nix-env.html",
+  "#ssec-version-comparisons": "command-ref/nix-env.html#versions",
+  "#sec-nix-hash": "command-ref/nix-hash.html",
+  "#sec-nix-instantiate": "command-ref/nix-instantiate.html",
+  "#sec-nix-prefetch-url": "command-ref/nix-prefetch-url.html",
+  "#sec-nix-shell": "command-ref/nix-shell.html",
+  "#ssec-nix-shell-shebang": "command-ref/nix-shell.html#use-as-a--interpreter",
+  "#nixref-queries": "command-ref/nix-store.html#queries",
+  "#opt-add-root": "command-ref/nix-store.html#opt-add-root",
+  "#refsec-nix-store-dump": "command-ref/nix-store.html#operation---dump",
+  "#refsec-nix-store-export": "command-ref/nix-store.html#operation---export",
+  "#refsec-nix-store-import": "command-ref/nix-store.html#operation---import",
+  "#refsec-nix-store-query": "command-ref/nix-store.html#operation---query",
+  "#refsec-nix-store-verify": "command-ref/nix-store.html#operation---verify",
+  "#rsec-nix-store-gc": "command-ref/nix-store.html#operation---gc",
+  "#rsec-nix-store-generate-binary-cache-key": "command-ref/nix-store.html#operation---generate-binary-cache-key",
+  "#rsec-nix-store-realise": "command-ref/nix-store.html#operation---realise",
+  "#rsec-nix-store-serve": "command-ref/nix-store.html#operation---serve",
+  "#sec-nix-store": "command-ref/nix-store.html",
+  "#opt-I": "command-ref/opt-common.html#opt-I",
+  "#opt-attr": "command-ref/opt-common.html#opt-attr",
+  "#opt-common": "command-ref/opt-common.html",
+  "#opt-cores": "command-ref/opt-common.html#opt-cores",
+  "#opt-log-format": "command-ref/opt-common.html#opt-log-format",
+  "#opt-max-jobs": "command-ref/opt-common.html#opt-max-jobs",
+  "#opt-max-silent-time": "command-ref/opt-common.html#opt-max-silent-time",
+  "#opt-timeout": "command-ref/opt-common.html#opt-timeout",
+  "#sec-common-options": "command-ref/opt-common.html",
+  "#ch-utilities": "command-ref/utilities.html",
+  "#chap-hacking": "contributing/hacking.html",
+  "#adv-attr-allowSubstitutes": "language/advanced-attributes.html#adv-attr-allowSubstitutes",
+  "#adv-attr-allowedReferences": "language/advanced-attributes.html#adv-attr-allowedReferences",
+  "#adv-attr-allowedRequisites": "language/advanced-attributes.html#adv-attr-allowedRequisites",
+  "#adv-attr-disallowedReferences": "language/advanced-attributes.html#adv-attr-disallowedReferences",
+  "#adv-attr-disallowedRequisites": "language/advanced-attributes.html#adv-attr-disallowedRequisites",
+  "#adv-attr-exportReferencesGraph": "language/advanced-attributes.html#adv-attr-exportReferencesGraph",
+  "#adv-attr-impureEnvVars": "language/advanced-attributes.html#adv-attr-impureEnvVars",
+  "#adv-attr-outputHash": "language/advanced-attributes.html#adv-attr-outputHash",
+  "#adv-attr-outputHashAlgo": "language/advanced-attributes.html#adv-attr-outputHashAlgo",
+  "#adv-attr-outputHashMode": "language/advanced-attributes.html#adv-attr-outputHashMode",
+  "#adv-attr-passAsFile": "language/advanced-attributes.html#adv-attr-passAsFile",
+  "#adv-attr-preferLocalBuild": "language/advanced-attributes.html#adv-attr-preferLocalBuild",
+  "#fixed-output-drvs": "language/advanced-attributes.html#adv-attr-outputHash",
+  "#sec-advanced-attributes": "language/advanced-attributes.html",
+  "#builtin-abort": "language/builtins.html#builtins-abort",
+  "#builtin-add": "language/builtins.html#builtins-add",
+  "#builtin-all": "language/builtins.html#builtins-all",
+  "#builtin-any": "language/builtins.html#builtins-any",
+  "#builtin-attrNames": "language/builtins.html#builtins-attrNames",
+  "#builtin-attrValues": "language/builtins.html#builtins-attrValues",
+  "#builtin-baseNameOf": "language/builtins.html#builtins-baseNameOf",
+  "#builtin-bitAnd": "language/builtins.html#builtins-bitAnd",
+  "#builtin-bitOr": "language/builtins.html#builtins-bitOr",
+  "#builtin-bitXor": "language/builtins.html#builtins-bitXor",
+  "#builtin-builtins": "language/builtins.html#builtins-builtins",
+  "#builtin-compareVersions": "language/builtins.html#builtins-compareVersions",
+  "#builtin-concatLists": "language/builtins.html#builtins-concatLists",
+  "#builtin-concatStringsSep": "language/builtins.html#builtins-concatStringsSep",
+  "#builtin-currentSystem": "language/builtins.html#builtins-currentSystem",
+  "#builtin-deepSeq": "language/builtins.html#builtins-deepSeq",
+  "#builtin-derivation": "language/builtins.html#builtins-derivation",
+  "#builtin-dirOf": "language/builtins.html#builtins-dirOf",
+  "#builtin-div": "language/builtins.html#builtins-div",
+  "#builtin-elem": "language/builtins.html#builtins-elem",
+  "#builtin-elemAt": "language/builtins.html#builtins-elemAt",
+  "#builtin-fetchGit": "language/builtins.html#builtins-fetchGit",
+  "#builtin-fetchTarball": "language/builtins.html#builtins-fetchTarball",
+  "#builtin-fetchurl": "language/builtins.html#builtins-fetchurl",
+  "#builtin-filterSource": "language/builtins.html#builtins-filterSource",
+  "#builtin-foldl-prime": "language/builtins.html#builtins-foldl-prime",
+  "#builtin-fromJSON": "language/builtins.html#builtins-fromJSON",
+  "#builtin-functionArgs": "language/builtins.html#builtins-functionArgs",
+  "#builtin-genList": "language/builtins.html#builtins-genList",
+  "#builtin-getAttr": "language/builtins.html#builtins-getAttr",
+  "#builtin-getEnv": "language/builtins.html#builtins-getEnv",
+  "#builtin-hasAttr": "language/builtins.html#builtins-hasAttr",
+  "#builtin-hashFile": "language/builtins.html#builtins-hashFile",
+  "#builtin-hashString": "language/builtins.html#builtins-hashString",
+  "#builtin-head": "language/builtins.html#builtins-head",
+  "#builtin-import": "language/builtins.html#builtins-import",
+  "#builtin-intersectAttrs": "language/builtins.html#builtins-intersectAttrs",
+  "#builtin-isAttrs": "language/builtins.html#builtins-isAttrs",
+  "#builtin-isBool": "language/builtins.html#builtins-isBool",
+  "#builtin-isFloat": "language/builtins.html#builtins-isFloat",
+  "#builtin-isFunction": "language/builtins.html#builtins-isFunction",
+  "#builtin-isInt": "language/builtins.html#builtins-isInt",
+  "#builtin-isList": "language/builtins.html#builtins-isList",
+  "#builtin-isNull": "language/builtins.html#builtins-isNull",
+  "#builtin-isString": "language/builtins.html#builtins-isString",
+  "#builtin-length": "language/builtins.html#builtins-length",
+  "#builtin-lessThan": "language/builtins.html#builtins-lessThan",
+  "#builtin-listToAttrs": "language/builtins.html#builtins-listToAttrs",
+  "#builtin-map": "language/builtins.html#builtins-map",
+  "#builtin-match": "language/builtins.html#builtins-match",
+  "#builtin-mul": "language/builtins.html#builtins-mul",
+  "#builtin-parseDrvName": "language/builtins.html#builtins-parseDrvName",
+  "#builtin-path": "language/builtins.html#builtins-path",
+  "#builtin-pathExists": "language/builtins.html#builtins-pathExists",
+  "#builtin-placeholder": "language/builtins.html#builtins-placeholder",
+  "#builtin-readDir": "language/builtins.html#builtins-readDir",
+  "#builtin-readFile": "language/builtins.html#builtins-readFile",
+  "#builtin-removeAttrs": "language/builtins.html#builtins-removeAttrs",
+  "#builtin-replaceStrings": "language/builtins.html#builtins-replaceStrings",
+  "#builtin-seq": "language/builtins.html#builtins-seq",
+  "#builtin-sort": "language/builtins.html#builtins-sort",
+  "#builtin-split": "language/builtins.html#builtins-split",
+  "#builtin-splitVersion": "language/builtins.html#builtins-splitVersion",
+  "#builtin-stringLength": "language/builtins.html#builtins-stringLength",
+  "#builtin-sub": "language/builtins.html#builtins-sub",
+  "#builtin-substring": "language/builtins.html#builtins-substring",
+  "#builtin-tail": "language/builtins.html#builtins-tail",
+  "#builtin-throw": "language/builtins.html#builtins-throw",
+  "#builtin-toFile": "language/builtins.html#builtins-toFile",
+  "#builtin-toJSON": "language/builtins.html#builtins-toJSON",
+  "#builtin-toPath": "language/builtins.html#builtins-toPath",
+  "#builtin-toString": "language/builtins.html#builtins-toString",
+  "#builtin-toXML": "language/builtins.html#builtins-toXML",
+  "#builtin-trace": "language/builtins.html#builtins-trace",
+  "#builtin-tryEval": "language/builtins.html#builtins-tryEval",
+  "#builtin-typeOf": "language/builtins.html#builtins-typeOf",
+  "#ssec-builtins": "language/builtins.html",
+  "#attr-system": "language/derivations.html#attr-system",
+  "#ssec-derivation": "language/derivations.html",
+  "#ch-expression-language": "language/index.html",
+  "#sec-constructs": "language/constructs.html",
+  "#sect-let-language": "language/constructs.html#let-language",
+  "#ss-functions": "language/constructs.html#functions",
+  "#sec-language-operators": "language/operators.html",
+  "#table-operators": "language/operators.html",
+  "#ssec-values": "language/values.html",
+  "#gloss-closure": "glossary.html#gloss-closure",
+  "#gloss-derivation": "glossary.html#gloss-derivation",
+  "#gloss-deriver": "glossary.html#gloss-deriver",
+  "#gloss-nar": "glossary.html#gloss-nar",
+  "#gloss-output-path": "glossary.html#gloss-output-path",
+  "#gloss-profile": "glossary.html#gloss-profile",
+  "#gloss-reachable": "glossary.html#gloss-reachable",
+  "#gloss-reference": "glossary.html#gloss-reference",
+  "#gloss-substitute": "glossary.html#gloss-substitute",
+  "#gloss-user-env": "glossary.html#gloss-user-env",
+  "#gloss-validity": "glossary.html#gloss-validity",
+  "#part-glossary": "glossary.html",
+  "#sec-building-source": "installation/building-source.html",
+  "#ch-env-variables": "installation/env-variables.html",
+  "#sec-installer-proxy-settings": "installation/env-variables.html#proxy-environment-variables",
+  "#sec-nix-ssl-cert-file": "installation/env-variables.html#nix_ssl_cert_file",
+  "#sec-nix-ssl-cert-file-with-nix-daemon-and-macos": "installation/env-variables.html#nix_ssl_cert_file-with-macos-and-the-nix-daemon",
+  "#chap-installation": "installation/installation.html",
+  "#ch-installing-binary": "installation/installing-binary.html",
+  "#sect-macos-installation": "installation/installing-binary.html#macos-installation",
+  "#sect-macos-installation-change-store-prefix": "installation/installing-binary.html#macos-installation",
+  "#sect-macos-installation-encrypted-volume": "installation/installing-binary.html#macos-installation",
+  "#sect-macos-installation-recommended-notes": "installation/installing-binary.html#macos-installation",
+  "#sect-macos-installation-symlink": "installation/installing-binary.html#macos-installation",
+  "#sect-multi-user-installation": "installation/installing-binary.html#multi-user-installation",
+  "#sect-nix-install-binary-tarball": "installation/installing-binary.html#installing-from-a-binary-tarball",
+  "#sect-nix-install-pinned-version-url": "installation/installing-binary.html#installing-a-pinned-nix-version-from-a-url",
+  "#sect-single-user-installation": "installation/installing-binary.html#single-user-installation",
+  "#ch-installing-source": "installation/installing-source.html",
+  "#ssec-multi-user": "installation/multi-user.html",
+  "#ch-nix-security": "installation/nix-security.html",
+  "#sec-obtaining-source": "installation/obtaining-source.html",
+  "#sec-prerequisites-source": "installation/prerequisites-source.html",
+  "#sec-single-user": "installation/single-user.html",
+  "#ch-supported-platforms": "installation/supported-platforms.html",
+  "#ch-upgrading-nix": "installation/upgrading.html",
+  "#ch-about-nix": "introduction.html",
+  "#chap-introduction": "introduction.html",
+  "#ch-basic-package-mgmt": "package-management/basic-package-mgmt.html",
+  "#ssec-binary-cache-substituter": "package-management/binary-cache-substituter.html",
+  "#sec-channels": "package-management/channels.html",
+  "#ssec-copy-closure": "package-management/copy-closure.html",
+  "#sec-garbage-collection": "package-management/garbage-collection.html",
+  "#ssec-gc-roots": "package-management/garbage-collector-roots.html",
+  "#chap-package-management": "package-management/package-management.html",
+  "#sec-profiles": "package-management/profiles.html",
+  "#ssec-s3-substituter": "package-management/s3-substituter.html",
+  "#ssec-s3-substituter-anonymous-reads": "package-management/s3-substituter.html#anonymous-reads-to-your-s3-compatible-binary-cache",
+  "#ssec-s3-substituter-authenticated-reads": "package-management/s3-substituter.html#authenticated-reads-to-your-s3-binary-cache",
+  "#ssec-s3-substituter-authenticated-writes": "package-management/s3-substituter.html#authenticated-writes-to-your-s3-compatible-binary-cache",
+  "#sec-sharing-packages": "package-management/sharing-packages.html",
+  "#ssec-ssh-substituter": "package-management/ssh-substituter.html",
+  "#chap-quick-start": "quick-start.html",
+  "#sec-relnotes": "release-notes/release-notes.html",
+  "#ch-relnotes-0.10.1": "release-notes/rl-0.10.1.html",
+  "#ch-relnotes-0.10": "release-notes/rl-0.10.html",
+  "#ssec-relnotes-0.11": "release-notes/rl-0.11.html",
+  "#ssec-relnotes-0.12": "release-notes/rl-0.12.html",
+  "#ssec-relnotes-0.13": "release-notes/rl-0.13.html",
+  "#ssec-relnotes-0.14": "release-notes/rl-0.14.html",
+  "#ssec-relnotes-0.15": "release-notes/rl-0.15.html",
+  "#ssec-relnotes-0.16": "release-notes/rl-0.16.html",
+  "#ch-relnotes-0.5": "release-notes/rl-0.5.html",
+  "#ch-relnotes-0.6": "release-notes/rl-0.6.html",
+  "#ch-relnotes-0.7": "release-notes/rl-0.7.html",
+  "#ch-relnotes-0.8.1": "release-notes/rl-0.8.1.html",
+  "#ch-relnotes-0.8": "release-notes/rl-0.8.html",
+  "#ch-relnotes-0.9.1": "release-notes/rl-0.9.1.html",
+  "#ch-relnotes-0.9.2": "release-notes/rl-0.9.2.html",
+  "#ch-relnotes-0.9": "release-notes/rl-0.9.html",
+  "#ssec-relnotes-1.0": "release-notes/rl-1.0.html",
+  "#ssec-relnotes-1.1": "release-notes/rl-1.1.html",
+  "#ssec-relnotes-1.10": "release-notes/rl-1.10.html",
+  "#ssec-relnotes-1.11.10": "release-notes/rl-1.11.10.html",
+  "#ssec-relnotes-1.11": "release-notes/rl-1.11.html",
+  "#ssec-relnotes-1.2": "release-notes/rl-1.2.html",
+  "#ssec-relnotes-1.3": "release-notes/rl-1.3.html",
+  "#ssec-relnotes-1.4": "release-notes/rl-1.4.html",
+  "#ssec-relnotes-1.5.1": "release-notes/rl-1.5.1.html",
+  "#ssec-relnotes-1.5.2": "release-notes/rl-1.5.2.html",
+  "#ssec-relnotes-1.5": "release-notes/rl-1.5.html",
+  "#ssec-relnotes-1.6.1": "release-notes/rl-1.6.1.html",
+  "#ssec-relnotes-1.6.0": "release-notes/rl-1.6.html",
+  "#ssec-relnotes-1.7": "release-notes/rl-1.7.html",
+  "#ssec-relnotes-1.8": "release-notes/rl-1.8.html",
+  "#ssec-relnotes-1.9": "release-notes/rl-1.9.html",
+  "#ssec-relnotes-2.0": "release-notes/rl-2.0.html",
+  "#ssec-relnotes-2.1": "release-notes/rl-2.1.html",
+  "#ssec-relnotes-2.2": "release-notes/rl-2.2.html",
+  "#ssec-relnotes-2.3": "release-notes/rl-2.3.html"
+};
+
+var isRoot = (document.location.pathname.endsWith('/') || document.location.pathname.endsWith('/index.html')) && path_to_root === '';
+if (isRoot && redirects[document.location.hash]) {
+  document.location.href = path_to_root + redirects[document.location.hash];
+}
diff --git a/doc/manual/src/SUMMARY.md.in b/doc/manual/src/SUMMARY.md.in
index 860222337..9b66ec3db 100644
--- a/doc/manual/src/SUMMARY.md.in
+++ b/doc/manual/src/SUMMARY.md.in
@@ -26,21 +26,14 @@
     - [Copying Closures via SSH](package-management/copy-closure.md)
     - [Serving a Nix store via SSH](package-management/ssh-substituter.md)
     - [Serving a Nix store via S3](package-management/s3-substituter.md)
-- [Writing Nix Expressions](expressions/writing-nix-expressions.md)
-  - [A Simple Nix Expression](expressions/simple-expression.md)
-    - [Expression Syntax](expressions/expression-syntax.md)
-    - [Build Script](expressions/build-script.md)
-    - [Arguments and Variables](expressions/arguments-variables.md)
-    - [Building and Testing](expressions/simple-building-testing.md)
-    - [Generic Builder Syntax](expressions/generic-builder.md)
-  - [Writing Nix Expressions](expressions/expression-language.md)
-    - [Values](expressions/language-values.md)
-    - [Language Constructs](expressions/language-constructs.md)
-    - [Operators](expressions/language-operators.md)
-    - [Derivations](expressions/derivations.md)
-      - [Advanced Attributes](expressions/advanced-attributes.md)
-    - [Built-in Constants](expressions/builtin-constants.md)
-    - [Built-in Functions](expressions/builtins.md)
+- [Nix Language](language/index.md)
+  - [Data Types](language/values.md)
+  - [Language Constructs](language/constructs.md)
+  - [Operators](language/operators.md)
+  - [Derivations](language/derivations.md)
+    - [Advanced Attributes](language/advanced-attributes.md)
+  - [Built-in Constants](language/builtin-constants.md)
+  - [Built-in Functions](language/builtins.md)
 - [Advanced Topics](advanced-topics/advanced-topics.md)
   - [Remote Builds](advanced-topics/distributed-builds.md)
   - [Tuning Cores and Jobs](advanced-topics/cores-vs-jobs.md)
@@ -66,12 +59,23 @@
 @manpages@
   - [Files](command-ref/files.md)
     - [nix.conf](command-ref/conf-file.md)
+<!--
+- [Architecture](architecture/architecture.md)
+  - [Store](architecture/store/store.md)
+    - [Closure](architecture/store/store/closure.md)
+    - [Build system terminology](architecture/store/store/build-system-terminology.md)
+  - [Store Path](architecture/store/path.md)
+  - [File System Object](architecture/store/fso.md)
+-->
 - [Glossary](glossary.md)
 - [Contributing](contributing/contributing.md)
   - [Hacking](contributing/hacking.md)
   - [CLI guideline](contributing/cli-guideline.md)
 - [Release Notes](release-notes/release-notes.md)
   - [Release X.Y (202?-??-??)](release-notes/rl-next.md)
+  - [Release 2.11 (2022-08-25)](release-notes/rl-2.11.md)
+  - [Release 2.10 (2022-07-11)](release-notes/rl-2.10.md)
+  - [Release 2.9 (2022-05-30)](release-notes/rl-2.9.md)
   - [Release 2.8 (2022-04-19)](release-notes/rl-2.8.md)
   - [Release 2.7 (2022-03-07)](release-notes/rl-2.7.md)
   - [Release 2.6 (2022-01-24)](release-notes/rl-2.6.md)
diff --git a/doc/manual/src/advanced-topics/diff-hook.md b/doc/manual/src/advanced-topics/diff-hook.md
index 7a2622b3d..161e64b2a 100644
--- a/doc/manual/src/advanced-topics/diff-hook.md
+++ b/doc/manual/src/advanced-topics/diff-hook.md
@@ -101,7 +101,7 @@ In particular, notice the
 `/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable.check` output. Nix
 has copied the build results to that directory where you can examine it.
 
-> **Note**
+> []{#check-dirs-are-unregistered} **Note**
 > 
 > Check paths are not protected against garbage collection, and this
 > path will be deleted on the next garbage collection.
diff --git a/doc/manual/src/advanced-topics/distributed-builds.md b/doc/manual/src/advanced-topics/distributed-builds.md
index b0d7fbf1a..fefd10100 100644
--- a/doc/manual/src/advanced-topics/distributed-builds.md
+++ b/doc/manual/src/advanced-topics/distributed-builds.md
@@ -12,14 +12,14 @@ machine is accessible via SSH and that it has Nix installed. You can
 test whether connecting to the remote Nix instance works, e.g.
 
 ```console
-$ nix ping-store --store ssh://mac
+$ nix store ping --store ssh://mac
 ```
 
 will try to connect to the machine named `mac`. It is possible to
 specify an SSH identity file as part of the remote store URI, e.g.
 
 ```console
-$ nix ping-store --store ssh://mac?ssh-key=/home/alice/my-key
+$ nix store ping --store ssh://mac?ssh-key=/home/alice/my-key
 ```
 
 Since builds should be non-interactive, the key should not have a
diff --git a/doc/manual/src/architecture/architecture.md b/doc/manual/src/architecture/architecture.md
new file mode 100644
index 000000000..41deb07af
--- /dev/null
+++ b/doc/manual/src/architecture/architecture.md
@@ -0,0 +1,79 @@
+# Architecture
+
+*(This chapter is unstable and a work in progress. Incoming links may rot.)*
+
+This chapter describes how Nix works.
+It should help users understand why Nix behaves as it does, and it should help developers understand how to modify Nix and how to write similar tools.
+
+## Overview
+
+Nix consists of [hierarchical layers][layer-architecture].
+
+```
++-----------------------------------------------------------------+
+| Nix                                                             |
+|                  [ commmand line interface ]------,             |
+|                               |                   |             |
+|                           evaluates               |             |
+|                               |                manages          |
+|                               V                   |             |
+|                  [ configuration language  ]      |             |
+|                               |                   |             |
+| +-----------------------------|-------------------V-----------+ |
+| | store                  evaluates to                         | |
+| |                             |                               | |
+| |             referenced by   V       builds                  | |
+| |  [ build input ] ---> [ build plan ] ---> [ build result ]  | |
+| |                                                             | |
+| +-------------------------------------------------------------+ |
++-----------------------------------------------------------------+
+```
+
+At the top is the [command line interface](../command-ref/command-ref.md), translating from invocations of Nix executables to interactions with the underlying layers.
+
+Below that is the [Nix expression language](../expressions/expression-language.md), a [purely functional][purely-functional-programming] configuration language.
+It is used to compose expressions which ultimately evaluate to self-contained *build plans*, used to derive *build results* from referenced *build inputs*.
+
+The command line and Nix language are what users interact with most.
+
+> **Note**
+> The Nix language itself does not have a notion of *packages* or *configurations*.
+> As far as we are concerned here, the inputs and results of a build plan are just data.
+
+Underlying these is the [Nix store](./store/store.md), a mechanism to keep track of build plans, data, and references between them.
+It can also execute build plans to produce new data.
+
+A build plan is a series of *build tasks*.
+Each build task has a special build input which is used as *build instructions*.
+The result of a build task can be input to another build task.
+
+```
++-----------------------------------------------------------------------------------------+
+| store                                                                                   |
+|                   .................................................                     |
+|                   :  build plan                                   :                     |
+|                   :                                               :                     |
+|  [ build input ]-----instructions-,                               :                     |
+|                   :               |                               :                     |
+|                   :               v                               :                     |
+|  [ build input ]----------->[ build task ]--instructions-,        :                     |
+|                   :                                      |        :                     |
+|                   :                                      |        :                     |
+|                   :                                      v        :                     |
+|                   :                               [ build task ]----->[ build result ]  |
+|  [ build input ]-----instructions-,                      ^        :                     |
+|                   :               |                      |        :                     |
+|                   :               v                      |        :                     |
+|  [ build input ]----------->[ build task ]---------------'        :                     |
+|                   :               ^                               :                     |
+|                   :               |                               :                     |
+|  [ build input ]------------------'                               :                     |
+|                   :                                               :                     |
+|                   :                                               :                     |
+|                   :...............................................:                     |
+|                                                                                         |
++-----------------------------------------------------------------------------------------+
+```
+
+[layer-architecture]: https://en.m.wikipedia.org/wiki/Multitier_architecture#Layers
+[purely-functional-programming]: https://en.m.wikipedia.org/wiki/Purely_functional_programming
diff --git a/doc/manual/src/architecture/store/fso.md b/doc/manual/src/architecture/store/fso.md
new file mode 100644
index 000000000..e0eb69f60
--- /dev/null
+++ b/doc/manual/src/architecture/store/fso.md
@@ -0,0 +1,69 @@
+# File System Object
+
+The Nix store uses a simple file system model for the data it holds in [store objects](store.md#store-object).
+
+Every file system object is one of the following:
+
+ - File: an executable flag, and arbitrary data for contents
+ - Directory: mapping of names to child file system objects
+ - [Symbolic link][symlink]: may point anywhere.
+
+We call a store object's outermost file system object the *root*.
+
+    data FileSystemObject
+      = File      { isExecutable :: Bool, contents :: Bytes }
+      | Directory { entries :: Map FileName FileSystemObject }
+      | SymLink   { target :: Path }
+
+Examples:
+
+- a directory with contents
+
+      /nix/store/<hash>-hello-2.10
+      ├── bin
+      │   └── hello
+      └── share
+          ├── info
+          │   └── hello.info
+          └── man
+              └── man1
+                  └── hello.1.gz
+
+- a directory with relative symlink and other contents
+
+      /nix/store/<hash>-go-1.16.9
+      ├── bin -> share/go/bin
+      ├── nix-support/
+      └── share/
+
+- a directory with absolute symlink
+
+      /nix/store/d3k...-nodejs
+      └── nix_node -> /nix/store/f20...-nodejs-10.24.
+
+A bare file or symlink can be a root file system object.
+Examples:
+
+    /nix/store/<hash>-hello-2.10.tar.gz
+
+    /nix/store/4j5...-pkg-config-wrapper-0.29.2-doc -> /nix/store/i99...-pkg-config-0.29.2-doc
+
+Symlinks pointing outside of their own root or to a store object without a matching reference are allowed, but might not function as intended.
+Examples:
+
+- an arbitrarily symlinked file may change or not exist at all
+
+      /nix/store/<hash>-foo
+      └── foo -> /home/foo
+
+- if a symlink to a store path was not automatically created by Nix, it may be invalid or get invalidated when the store object is deleted
+
+      /nix/store/<hash>-bar
+      └── bar -> /nix/store/abc...-foo
+
+Nix file system objects do not support [hard links][hardlink]:
+each file system object which is not the root has exactly one parent and one name.
+However, as store objects are immutable, an underlying file system can use hard links for optimization.
+
+[symlink]: https://en.m.wikipedia.org/wiki/Symbolic_link
+[hardlink]: https://en.m.wikipedia.org/wiki/Hard_link
diff --git a/doc/manual/src/architecture/store/path.md b/doc/manual/src/architecture/store/path.md
new file mode 100644
index 000000000..663f04f46
--- /dev/null
+++ b/doc/manual/src/architecture/store/path.md
@@ -0,0 +1,105 @@
+# Store Path
+
+Nix implements [references](store.md#reference) to [store objects](store.md#store-object) as *store paths*.
+
+Store paths are pairs of
+
+- a 20-byte [digest](#digest) for identification
+- a symbolic name for people to read.
+
+Example:
+
+- digest: `b6gvzjyb2pg0kjfwrjmg1vfhh54ad73z`
+- name:   `firefox-33.1`
+
+It is rendered to a file system path as the concatenation of
+
+  - [store directory](#store-directory)
+  - path-separator (`/`)
+  - [digest](#digest) rendered in a custom variant of [base-32](https://en.m.wikipedia.org/wiki/Base32) (20 arbitrary bytes become 32 ASCII characters)
+  - hyphen (`-`)
+  - name
+
+Example:
+
+      /nix/store/b6gvzjyb2pg0kjfwrjmg1vfhh54ad73z-firefox-33.1
+      |--------| |------------------------------| |----------|
+    store directory            digest                 name
+
+## Store Directory
+
+Every [store](./store.md) has a store directory.
+
+If the store has a [file system representation](./store.md#files-and-processes), this directory contains the store’s [file system objects](#file-system-object), which can be addressed by [store paths](#store-path).
+
+This means a store path is not just derived from the referenced store object itself, but depends on the store the store object is in.
+
+> **Note**
+> The store directory defaults to `/nix/store`, but is in principle arbitrary.
+
+It is important which store a given store object belongs to:
+Files in the store object can contain store paths, and processes may read these paths.
+Nix can only guarantee [referential integrity](store/closure.md) if store paths do not cross store boundaries.
+
+Therefore one can only copy store objects to a different store if
+
+- the source and target stores' directories match
+
+  or
+
+- the store object in question has no references, that is, contains no store paths.
+
+One cannot copy a store object to a store with a different store directory.
+Instead, it has to be rebuilt, together with all its dependencies.
+It is in general not enough to replace the store directory string in file contents, as this may render executables unusable by invalidating their internal offsets or checksums.
+
+# Digest
+
+In a [store path](#store-path), the [digest][digest] is the output of a [cryptographic hash function][hash] of either all *inputs* involved in building the referenced store object or its actual *contents*.
+
+Store objects are therefore said to be either [input-addressed](#input-addressing) or [content-addressed](#content-addressing).
+
+> **Historical Note**
+> The 20 byte restriction is because originally digests were [SHA-1][sha-1] hashes.
+> Nix now uses [SHA-256][sha-256], and longer hashes are still reduced to 20 bytes for compatibility.
+
+[digest]: https://en.m.wiktionary.org/wiki/digest#Noun
+[hash]: https://en.m.wikipedia.org/wiki/Cryptographic_hash_function
+[sha-1]: https://en.m.wikipedia.org/wiki/SHA-1
+[sha-256]: https://en.m.wikipedia.org/wiki/SHA-256
+
+### Reference scanning
+
+When a new store object is built, Nix scans its file contents for store paths to construct its set of references.
+
+The special format of a store path's [digest](#digest) allows reliably detecting it among arbitrary data.
+Nix uses the [closure](store.md#closure) of build inputs to derive the list of allowed store paths, to avoid false positives.
+
+This way, scanning files captures run time dependencies without the user having to declare them explicitly.
+Doing it at build time and persisting references in the store object avoids repeating this time-consuming operation.
+
+> **Note**
+> In practice, it is sometimes still necessary for users to declare certain dependencies explicitly, if they are to be preserved in the build result's closure.
+This depends on the specifics of the software to build and run.
+>
+> For example, Java programs are compressed after compilation, which obfuscates any store paths they may refer to and prevents Nix from automatically detecting them.
+
+## Input Addressing
+
+Input addressing means that the digest derives from how the store object was produced, namely its build inputs and build plan.
+
+To compute the hash of a store object one needs a deterministic serialisation, i.e., a binary string representation which only changes if the store object changes.
+
+Nix has a custom serialisation format called Nix Archive (NAR)
+
+Store object references of this sort can *not* be validated from the content of the store object.
+Rather, a cryptographic signature has to be used to indicate that someone is vouching for the store object really being produced from a build plan with that digest.
+
+## Content Addressing
+
+Content addressing means that the digest derives from the store object's contents, namely its file system objects and references.
+If one knows content addressing was used, one can recalculate the reference and thus verify the store object.
+
+Content addressing is currently only used for the special cases of source files and "fixed-output derivations", where the contents of a store object are known in advance.
+Content addressing of build results is still an [experimental feature subject to some restrictions](https://github.com/tweag/rfcs/blob/cas-rfc/rfcs/0062-content-addressed-paths.md).
+
diff --git a/doc/manual/src/architecture/store/store.md b/doc/manual/src/architecture/store/store.md
new file mode 100644
index 000000000..08b6701d5
--- /dev/null
+++ b/doc/manual/src/architecture/store/store.md
@@ -0,0 +1,151 @@
+# Store
+
+A Nix store is a collection of *store objects* with references between them.
+It supports operations to manipulate that collection.
+
+The following concept map is a graphical outline of this chapter.
+Arrows indicate suggested reading order.
+
+```
+                      ,--------------[ store ]----------------,
+                      |                  |                    |
+                      v                  v                    v
+               [ store object ]     [ closure ]--,      [ operations ]
+                      |               |   |      |        |        |
+                      v               |   |      v        v        |
+           [ files and processes ]    |   | [ garbage collection ] |
+               /          \           |   |                        |
+              v            v          |   v                        v
+[ file system object ] [ store path ] | [ derivation ]--->[ building ]
+                  |        ^      |   |                         |
+                  v        |      v   v                         |
+             [ digest ]----' [ reference scanning ]<------------'
+              /      \
+             v        v
+[ input addressing ] [ content addressing ]
+```
+
+## Store Object
+
+A store object can hold
+
+- arbitrary *data*
+- *references* to other store objects.
+
+Store objects can be build inputs, build results, or build tasks.
+
+Store objects are [immutable][immutable-object]: once created, they do not change until they are deleted.
+
+## Reference
+
+A store object reference is an [opaque][opaque-data-type], [unique identifier][unique-identifier]:
+The only way to obtain references is by adding or building store objects.
+A reference will always point to exactly one store object.
+
+## Operations
+
+A Nix store can *add*, *retrieve*, and *delete* store objects.
+
+                [ data ]
+                    |
+                    V
+    [ store ] ---> add ----> [ store' ]
+                    |
+                    V
+              [ reference ]
+
+<!-- -->
+
+              [ reference ]
+                    |
+                    V
+    [ store ] ---> get
+                    |
+                    V
+             [ store object ]
+
+<!-- -->
+
+              [ reference ]
+                    |
+                    V
+    [ store ] --> delete --> [ store' ]
+
+
+It can *perform builds*, that is, create new store objects by transforming build inputs into build outputs, using instructions from the build tasks.
+
+
+              [ reference ]
+                    |
+                    V
+    [ store ] --> build --(maybe)--> [ store' ]
+                             |
+                             V
+                       [ reference ]
+
+
+As it keeps track of references, it can [garbage-collect][garbage-collection] unused store objects.
+
+
+    [ store ] --> collect garbage --> [ store' ]
+
+## Files and Processes
+
+Nix maps between its store model and the [Unix paradigm][unix-paradigm] of [files and processes][file-descriptor], by encoding immutable store objects and opaque identifiers as file system primitives: files and directories, and paths.
+That allows processes to resolve references contained in files and thus access the contents of store objects.
+
+Store objects are therefore implemented as the pair of
+
+  - a [file system object](fso.md) for data
+  - a set of [store paths](path.md) for references.
+
+[unix-paradigm]: https://en.m.wikipedia.org/wiki/Everything_is_a_file
+[file-descriptor]: https://en.m.wikipedia.org/wiki/File_descriptor
+
+The following diagram shows a radical simplification of how Nix interacts with the operating system:
+It uses files as build inputs, and build outputs are files again.
+On the operating system, files can be run as processes, which in turn operate on files.
+A build function also amounts to an operating system process (not depicted).
+
+```
++-----------------------------------------------------------------+
+| Nix                                                             |
+|                  [ commmand line interface ]------,             |
+|                               |                   |             |
+|                           evaluates               |             |
+|                               |                manages          |
+|                               V                   |             |
+|                  [ configuration language  ]      |             |
+|                               |                   |             |
+| +-----------------------------|-------------------V-----------+ |
+| | store                  evaluates to                         | |
+| |                             |                               | |
+| |             referenced by   V       builds                  | |
+| |  [ build input ] ---> [ build plan ] ---> [ build result ]  | |
+| |         ^                                        |          | |
+| +---------|----------------------------------------|----------+ |
++-----------|----------------------------------------|------------+
+            |                                        |
+    file system object                          store path
+            |                                        |
++-----------|----------------------------------------|------------+
+| operating system        +------------+             |            |
+|           '------------ |            | <-----------'            |
+|                         |    file    |                          |
+|                     ,-- |            | <-,                      |
+|                     |   +------------+   |                      |
+|          execute as |                    | read, write, execute |
+|                     |   +------------+   |                      |
+|                     '-> |  process   | --'                      |
+|                         +------------+                          |
++-----------------------------------------------------------------+
+```
+
+There exist different types of stores, which all follow this model.
+Examples:
+- store on the local file system
+- remote store accessible via SSH
+- binary cache store accessible via HTTP
+
+To make store objects accessible to processes, stores ultimately have to expose store objects through the file system.
+
diff --git a/doc/manual/src/architecture/store/store/build-system-terminology.md b/doc/manual/src/architecture/store/store/build-system-terminology.md
new file mode 100644
index 000000000..eefbaa630
--- /dev/null
+++ b/doc/manual/src/architecture/store/store/build-system-terminology.md
@@ -0,0 +1,32 @@
+# A [Rosetta stone][rosetta-stone] for build system terminology
+
+The Nix store's design is comparable to other build systems.
+Usage of terms is, for historic reasons, not entirely consistent within the Nix ecosystem, and still subject to slow change.
+
+The following translation table points out similarities and equivalent terms, to help clarify their meaning and inform consistent use in the future.
+
+| generic build system             | Nix              | [Bazel][bazel]                                                       | [Build Systems à la Carte][bsalc] | programming language     |
+| -------------------------------- | ---------------- | -------------------------------------------------------------------- | --------------------------------- | ------------------------ |
+| data (build input, build result) | store object     | [artifact][bazel-artifact]                                           | value                             | value                    |
+| build instructions               | builder          | ([depends on action type][bazel-actions])                            | function                          | function                 |
+| build task                       | derivation       | [action][bazel-action]                                               | `Task`                            | [thunk][thunk]           |
+| build plan                       | derivation graph | [action graph][bazel-action-graph], [build graph][bazel-build-graph] | `Tasks`                           | [call graph][call-graph] |
+| build                            | build            | build                                                                | application of `Build`            | evaluation               |
+| persistence layer                | store            | [action cache][bazel-action-cache]                                   | `Store`                           | heap                     |
+
+All of these systems share features of [declarative programming][declarative-programming] languages, a key insight first put forward by Eelco Dolstra et al. in [Imposing a Memory Management Discipline on Software Deployment][immdsd] (2004), elaborated in his PhD thesis [The Purely Functional Software Deployment Model][phd-thesis] (2006), and further refined by Andrey Mokhov et al. in [Build Systems à la Carte][bsalc] (2018).
+
+[rosetta-stone]: https://en.m.wikipedia.org/wiki/Rosetta_Stone
+[bazel]: https://bazel.build/start/bazel-intro
+[bazel-artifact]: https://bazel.build/reference/glossary#artifact
+[bazel-actions]: https://docs.bazel.build/versions/main/skylark/lib/actions.html
+[bazel-action]: https://bazel.build/reference/glossary#action
+[bazel-action-graph]: https://bazel.build/reference/glossary#action-graph
+[bazel-build-graph]: https://bazel.build/reference/glossary#build-graph
+[bazel-action-cache]: https://bazel.build/reference/glossary#action-cache
+[thunk]: https://en.m.wikipedia.org/wiki/Thunk
+[call-graph]: https://en.m.wikipedia.org/wiki/Call_graph
+[declarative-programming]: https://en.m.wikipedia.org/wiki/Declarative_programming
+[immdsd]: https://edolstra.github.io/pubs/immdsd-icse2004-final.pdf
+[phd-thesis]: https://edolstra.github.io/pubs/phd-thesis.pdf
+[bsalc]: https://www.microsoft.com/en-us/research/uploads/prod/2018/03/build-systems.pdf
diff --git a/doc/manual/src/architecture/store/store/closure.md b/doc/manual/src/architecture/store/store/closure.md
new file mode 100644
index 000000000..065b95ffc
--- /dev/null
+++ b/doc/manual/src/architecture/store/store/closure.md
@@ -0,0 +1,29 @@
+# Closure
+
+Nix stores ensure [referential integrity][referential-integrity]: for each store object in the store, all the store objects it references must also be in the store.
+
+The set of all store objects reachable by following references from a given initial set of store objects is called a *closure*.
+
+Adding, building, copying and deleting store objects must be done in a way that preserves referential integrity:
+
+- A newly added store object cannot have references, unless it is a build task.
+
+- Build results must only refer to store objects in the closure of the build inputs.
+
+  Building a store object will add appropriate references, according to the build task.
+
+- Store objects being copied must refer to objects already in the destination store.
+
+  Recursive copying must either proceed in dependency order or be atomic.
+
+- We can only safely delete store objects which are not reachable from any reference still in use.
+
+  <!-- more details in section on garbage collection, link to it once it exists -->
+
+[referential-integrity]: https://en.m.wikipedia.org/wiki/Referential_integrity
+[garbage-collection]: https://en.m.wikipedia.org/wiki/Garbage_collection_(computer_science)
+[immutable-object]: https://en.m.wikipedia.org/wiki/Immutable_object
+[opaque-data-type]: https://en.m.wikipedia.org/wiki/Opaque_data_type
+[unique-identifier]: https://en.m.wikipedia.org/wiki/Unique_identifier
+
+
diff --git a/doc/manual/src/command-ref/env-common.md b/doc/manual/src/command-ref/env-common.md
index 6e2403461..3f3eb6915 100644
--- a/doc/manual/src/command-ref/env-common.md
+++ b/doc/manual/src/command-ref/env-common.md
@@ -2,11 +2,11 @@
 
 Most Nix commands interpret the following environment variables:
 
-  - `IN_NIX_SHELL`\
+  - [`IN_NIX_SHELL`]{#env-IN_NIX_SHELL}\
     Indicator that tells if the current environment was set up by
-    `nix-shell`. Since Nix 2.0 the values are `"pure"` and `"impure"`
+    `nix-shell`. It can have the values `pure` or `impure`.
 
-  - `NIX_PATH`\
+  - [`NIX_PATH`]{#env-NIX_PATH}\
     A colon-separated list of directories used to look up Nix
     expressions enclosed in angle brackets (i.e., `<path>`). For
     instance, the value
@@ -44,7 +44,7 @@ Most Nix commands interpret the following environment variables:
     The Nix search path can also be extended using the `-I` option to
     many Nix commands, which takes precedence over `NIX_PATH`.
 
-  - `NIX_IGNORE_SYMLINK_STORE`\
+  - [`NIX_IGNORE_SYMLINK_STORE`]{#env-NIX_IGNORE_SYMLINK_STORE}\
     Normally, the Nix store directory (typically `/nix/store`) is not
     allowed to contain any symlink components. This is to prevent
     “impure” builds. Builders sometimes “canonicalise” paths by
@@ -66,41 +66,41 @@ Most Nix commands interpret the following environment variables:
 
     Consult the mount 8 manual page for details.
 
-  - `NIX_STORE_DIR`\
+  - [`NIX_STORE_DIR`]{#env-NIX_STORE_DIR}\
     Overrides the location of the Nix store (default `prefix/store`).
 
-  - `NIX_DATA_DIR`\
+  - [`NIX_DATA_DIR`]{#env-NIX_DATA_DIR}\
     Overrides the location of the Nix static data directory (default
     `prefix/share`).
 
-  - `NIX_LOG_DIR`\
+  - [`NIX_LOG_DIR`]{#env-NIX_LOG_DIR}\
     Overrides the location of the Nix log directory (default
     `prefix/var/log/nix`).
 
-  - `NIX_STATE_DIR`\
+  - [`NIX_STATE_DIR`]{#env-NIX_STATE_DIR}\
     Overrides the location of the Nix state directory (default
     `prefix/var/nix`).
 
-  - `NIX_CONF_DIR`\
+  - [`NIX_CONF_DIR`]{#env-NIX_CONF_DIR}\
     Overrides the location of the system Nix configuration directory
     (default `prefix/etc/nix`).
 
-  - `NIX_CONFIG`\
+  - [`NIX_CONFIG`]{#env-NIX_CONFIG}\
     Applies settings from Nix configuration from the environment.
     The content is treated as if it was read from a Nix configuration file.
     Settings are separated by the newline character.
 
-  - `NIX_USER_CONF_FILES`\
+  - [`NIX_USER_CONF_FILES`]{#env-NIX_USER_CONF_FILES}\
     Overrides the location of the user Nix configuration files to load
     from (defaults to the XDG spec locations). The variable is treated
     as a list separated by the `:` token.
 
-  - `TMPDIR`\
+  - [`TMPDIR`]{#env-TMPDIR}\
     Use the specified directory to store temporary files. In particular,
     this includes temporary build directories; these can take up
     substantial amounts of disk space. The default is `/tmp`.
 
-  - `NIX_REMOTE`\
+  - [`NIX_REMOTE`]{#env-NIX_REMOTE}\
     This variable should be set to `daemon` if you want to use the Nix
     daemon to execute Nix operations. This is necessary in [multi-user
     Nix installations](../installation/multi-user.md). If the Nix
@@ -108,16 +108,16 @@ Most Nix commands interpret the following environment variables:
     should be set to `unix://path/to/socket`. Otherwise, it should be
     left unset.
 
-  - `NIX_SHOW_STATS`\
+  - [`NIX_SHOW_STATS`]{#env-NIX_SHOW_STATS}\
     If set to `1`, Nix will print some evaluation statistics, such as
     the number of values allocated.
 
-  - `NIX_COUNT_CALLS`\
+  - [`NIX_COUNT_CALLS`]{#env-NIX_COUNT_CALLS}\
     If set to `1`, Nix will print how often functions were called during
     Nix expression evaluation. This is useful for profiling your Nix
     expressions.
 
-  - `GC_INITIAL_HEAP_SIZE`\
+  - [`GC_INITIAL_HEAP_SIZE`]{#env-GC_INITIAL_HEAP_SIZE}\
     If Nix has been configured to use the Boehm garbage collector, this
     variable sets the initial size of the heap in bytes. It defaults to
     384 MiB. Setting it to a low value reduces memory consumption, but
diff --git a/doc/manual/src/command-ref/nix-build.md b/doc/manual/src/command-ref/nix-build.md
index 43de7a6e6..49c6f3f55 100644
--- a/doc/manual/src/command-ref/nix-build.md
+++ b/doc/manual/src/command-ref/nix-build.md
@@ -12,6 +12,12 @@
   [`--dry-run`]
   [{`--out-link` | `-o`} *outlink*]
 
+# Disambiguation
+
+This man page describes the command `nix-build`, which is distinct from `nix
+build`. For documentation on the latter, run `nix build --help` or see `man
+nix3-build`.
+
 # Description
 
 The `nix-build` command builds the derivations described by the Nix
@@ -47,16 +53,16 @@ All options not listed here are passed to `nix-store
 --realise`, except for `--arg` and `--attr` / `-A` which are passed to
 `nix-instantiate`.
 
-  - `--no-out-link`\
+  - [`--no-out-link`]{#opt-no-out-link}\
     Do not create a symlink to the output path. Note that as a result
     the output does not become a root of the garbage collector, and so
     might be deleted by `nix-store
                     --gc`.
 
-  - `--dry-run`\
+  - [`--dry-run`]{#opt-dry-run}\
     Show what store paths would be built or downloaded.
 
-  - `--out-link` / `-o` *outlink*\
+  - [`--out-link`]{#opt-out-link} / `-o` *outlink*\
     Change the name of the symlink to the output path created from
     `result` to *outlink*.
 
diff --git a/doc/manual/src/command-ref/nix-env.md b/doc/manual/src/command-ref/nix-env.md
index 8d6abaf52..a5df35d77 100644
--- a/doc/manual/src/command-ref/nix-env.md
+++ b/doc/manual/src/command-ref/nix-env.md
@@ -31,7 +31,7 @@ subcommand to be performed. These are documented below.
 Several commands, such as `nix-env -q` and `nix-env -i`, take a list of
 arguments that specify the packages on which to operate. These are
 extended regular expressions that must match the entire name of the
-package. (For details on regular expressions, see regex7.) The match is
+package. (For details on regular expressions, see **regex**(7).) The match is
 case-sensitive. The regular expression can optionally be followed by a
 dash and a version number; if omitted, any version of the package will
 match. Here are some examples:
@@ -198,7 +198,7 @@ a number of possible ways:
     another.
 
   - If `--from-expression` is given, *args* are Nix
-    [functions](../expressions/language-constructs.md#functions)
+    [functions](../language/constructs.md#functions)
     that are called with the active Nix expression as their single
     argument. The derivations returned by those function calls are
     installed. This allows derivations to be specified in an
@@ -412,7 +412,7 @@ The upgrade operation determines whether a derivation `y` is an upgrade
 of a derivation `x` by looking at their respective `name` attributes.
 The names (e.g., `gcc-3.3.1` are split into two parts: the package name
 (`gcc`), and the version (`3.3.1`). The version part starts after the
-first dash not followed by a letter. `x` is considered an upgrade of `y`
+first dash not followed by a letter. `y` is considered an upgrade of `x`
 if their package names match, and the version of `y` is higher than that
 of `x`.
 
diff --git a/doc/manual/src/command-ref/nix-instantiate.md b/doc/manual/src/command-ref/nix-instantiate.md
index 2e198daed..8f143729e 100644
--- a/doc/manual/src/command-ref/nix-instantiate.md
+++ b/doc/manual/src/command-ref/nix-instantiate.md
@@ -51,7 +51,7 @@ standard input.
   - `--strict`\
     When used with `--eval`, recursively evaluate list elements and
     attributes. Normally, such sub-expressions are left unevaluated
-    (since the Nix expression language is lazy).
+    (since the Nix language is lazy).
 
     > **Warning**
     >
@@ -66,7 +66,7 @@ standard input.
     When used with `--eval`, print the resulting value as an XML
     representation of the abstract syntax tree rather than as an ATerm.
     The schema is the same as that used by the [`toXML`
-    built-in](../expressions/builtins.md).
+    built-in](../language/builtins.md).
 
   - `--read-write-mode`\
     When used with `--eval`, perform evaluation in read/write mode so
diff --git a/doc/manual/src/command-ref/nix-shell.md b/doc/manual/src/command-ref/nix-shell.md
index a2b6d8a8e..840bccd25 100644
--- a/doc/manual/src/command-ref/nix-shell.md
+++ b/doc/manual/src/command-ref/nix-shell.md
@@ -15,6 +15,12 @@
   [`--keep` *name*]
   {{`--packages` | `-p`} {*packages* | *expressions*} … | [*path*]}
 
+# Disambiguation
+
+This man page describes the command `nix-shell`, which is distinct from `nix
+shell`. For documentation on the latter, run `nix shell --help` or see `man
+nix3-shell`.
+
 # Description
 
 The command `nix-shell` will build the dependencies of the specified
diff --git a/doc/manual/src/command-ref/nix-store.md b/doc/manual/src/command-ref/nix-store.md
index 7db9f0c1c..ecd838e8d 100644
--- a/doc/manual/src/command-ref/nix-store.md
+++ b/doc/manual/src/command-ref/nix-store.md
@@ -22,7 +22,7 @@ This section lists the options that are common to all operations. These
 options are allowed for every subcommand, though they may not always
 have an effect.
 
-  - `--add-root` *path*\
+  - [`--add-root`]{#opt-add-root} *path*\
     Causes the result of a realisation (`--realise` and
     `--force-realise`) to be registered as a root of the garbage
     collector. *path* will be created as a symlink to the resulting
@@ -121,7 +121,7 @@ Special exit codes:
   - `102`\
     Hash mismatch, the build output was rejected because it does not
     match the [`outputHash` attribute of the
-    derivation](../expressions/advanced-attributes.md).
+    derivation](../language/advanced-attributes.md).
 
   - `104`\
     Not deterministic, the build succeeded in check mode but the
diff --git a/doc/manual/src/command-ref/opt-common.md b/doc/manual/src/command-ref/opt-common.md
index 7ee1a26bc..e612c416f 100644
--- a/doc/manual/src/command-ref/opt-common.md
+++ b/doc/manual/src/command-ref/opt-common.md
@@ -2,13 +2,13 @@
 
 Most Nix commands accept the following command-line options:
 
-  - `--help`\
+  - [`--help`]{#opt-help}\
     Prints out a summary of the command syntax and exits.
 
-  - `--version`\
+  - [`--version`]{#opt-version}\
     Prints out the Nix version number on standard output and exits.
 
-  - `--verbose` / `-v`\
+  - [`--verbose`]{#opt-verbose} / `-v`\
     Increases the level of verbosity of diagnostic messages printed on
     standard error. For each Nix operation, the information printed on
     standard output is well-defined; any diagnostic information is
@@ -37,14 +37,14 @@ Most Nix commands accept the following command-line options:
       - 5\
         “Vomit”: print vast amounts of debug information.
 
-  - `--quiet`\
+  - [`--quiet`]{#opt-quiet}\
     Decreases the level of verbosity of diagnostic messages printed on
     standard error. This is the inverse option to `-v` / `--verbose`.
 
     This option may be specified repeatedly. See the previous verbosity
     levels list.
 
-  - `--log-format` *format*\
+  - [`--log-format`]{#opt-log-format} *format*\
     This option can be used to change the output of the log format, with
     *format* being one of:
 
@@ -66,14 +66,14 @@ Most Nix commands accept the following command-line options:
       - bar-with-logs\
         Display the raw logs, with the progress bar at the bottom.
 
-  - `--no-build-output` / `-Q`\
+  - [`--no-build-output`]{#opt-no-build-output} / `-Q`\
     By default, output written by builders to standard output and
     standard error is echoed to the Nix command's standard error. This
     option suppresses this behaviour. Note that the builder's standard
     output and error are always written to a log file in
     `prefix/nix/var/log/nix`.
 
-  - `--max-jobs` / `-j` *number*\
+  - [`--max-jobs`]{#opt-max-jobs} / `-j` *number*\
     Sets the maximum number of build jobs that Nix will perform in
     parallel to the specified number. Specify `auto` to use the number
     of CPUs in the system. The default is specified by the `max-jobs`
@@ -83,7 +83,7 @@ Most Nix commands accept the following command-line options:
     Setting it to `0` disallows building on the local machine, which is
     useful when you want builds to happen only on remote builders.
 
-  - `--cores`\
+  - [`--cores`]{#opt-cores}\
     Sets the value of the `NIX_BUILD_CORES` environment variable in
     the invocation of builders. Builders can use this variable at
     their discretion to control the maximum amount of parallelism. For
@@ -94,18 +94,18 @@ Most Nix commands accept the following command-line options:
     means that the builder should use all available CPU cores in the
     system.
 
-  - `--max-silent-time`\
+  - [`--max-silent-time`]{#opt-max-silent-time}\
     Sets the maximum number of seconds that a builder can go without
     producing any data on standard output or standard error. The
     default is specified by the `max-silent-time` configuration
     setting. `0` means no time-out.
 
-  - `--timeout`\
+  - [`--timeout`]{#opt-timeout}\
     Sets the maximum number of seconds that a builder can run. The
     default is specified by the `timeout` configuration setting. `0`
     means no timeout.
 
-  - `--keep-going` / `-k`\
+  - [`--keep-going`]{#opt-keep-going} / `-k`\
     Keep going in case of failed builds, to the greatest extent
     possible. That is, if building an input of some derivation fails,
     Nix will still build the other inputs, but not the derivation
@@ -113,13 +113,13 @@ Most Nix commands accept the following command-line options:
     for builds of substitutes), possibly killing builds in progress (in
     case of parallel or distributed builds).
 
-  - `--keep-failed` / `-K`\
+  - [`--keep-failed`]{#opt-keep-failed} / `-K`\
     Specifies that in case of a build failure, the temporary directory
     (usually in `/tmp`) in which the build takes place should not be
     deleted. The path of the build directory is printed as an
     informational message.
 
-  - `--fallback`\
+  - [`--fallback`]{#opt-fallback}\
     Whenever Nix attempts to build a derivation for which substitutes
     are known for each output path, but realising the output paths
     through the substitutes fails, fall back on building the derivation.
@@ -134,18 +134,18 @@ Most Nix commands accept the following command-line options:
     failure in obtaining the substitutes to lead to a full build from
     source (with the related consumption of resources).
 
-  - `--readonly-mode`\
+  - [`--readonly-mode`]{#opt-readonly-mode}\
     When this option is used, no attempt is made to open the Nix
     database. Most Nix operations do need database access, so those
     operations will fail.
 
-  - `--arg` *name* *value*\
+  - [`--arg`]{#opt-arg} *name* *value*\
     This option is accepted by `nix-env`, `nix-instantiate`,
     `nix-shell` and `nix-build`. When evaluating Nix expressions, the
     expression evaluator will automatically try to call functions that
     it encounters. It can automatically call functions for which every
     argument has a [default
-    value](../expressions/language-constructs.md#functions) (e.g.,
+    value](../language/constructs.md#functions) (e.g.,
     `{ argName ?  defaultValue }: ...`). With `--arg`, you can also
     call functions that have arguments without a default value (or
     override a default value). That is, if the evaluator encounters a
@@ -164,19 +164,19 @@ Most Nix commands accept the following command-line options:
 
     So if you call this Nix expression (e.g., when you do `nix-env -iA
     pkgname`), the function will be called automatically using the
-    value [`builtins.currentSystem`](../expressions/builtins.md) for
+    value [`builtins.currentSystem`](../language/builtins.md) for
     the `system` argument. You can override this using `--arg`, e.g.,
     `nix-env -iA pkgname --arg system \"i686-freebsd\"`. (Note that
     since the argument is a Nix string literal, you have to escape the
     quotes.)
 
-  - `--argstr` *name* *value*\
+  - [`--argstr`]{#opt-argstr} *name* *value*\
     This option is like `--arg`, only the value is not a Nix
     expression but a string. So instead of `--arg system
     \"i686-linux\"` (the outer quotes are to keep the shell happy) you
     can say `--argstr system i686-linux`.
 
-  - `--attr` / `-A` *attrPath*\
+  - [`--attr`]{#opt-attr} / `-A` *attrPath*\
     Select an attribute from the top-level Nix expression being
     evaluated. (`nix-env`, `nix-instantiate`, `nix-build` and
     `nix-shell` only.) The *attribute path* *attrPath* is a sequence
@@ -191,7 +191,7 @@ Most Nix commands accept the following command-line options:
     attribute of the fourth element of the array in the `foo` attribute
     of the top-level expression.
 
-  - `--expr` / `-E`\
+  - [`--expr`]{#opt-expr} / `-E`\
     Interpret the command line arguments as a list of Nix expressions to
     be parsed and evaluated, rather than as a list of file names of Nix
     expressions. (`nix-instantiate`, `nix-build` and `nix-shell` only.)
@@ -202,17 +202,17 @@ Most Nix commands accept the following command-line options:
     use, give your expression to the `nix-shell -p` convenience flag
     instead.
 
-  - `-I` *path*\
+  - [`-I`]{#opt-I} *path*\
     Add a path to the Nix expression search path. This option may be
     given multiple times. See the `NIX_PATH` environment variable for
     information on the semantics of the Nix search path. Paths added
     through `-I` take precedence over `NIX_PATH`.
 
-  - `--option` *name* *value*\
+  - [`--option`]{#opt-option} *name* *value*\
     Set the Nix configuration option *name* to *value*. This overrides
     settings in the Nix configuration file (see nix.conf5).
 
-  - `--repair`\
+  - [`--repair`]{#opt-repair}\
     Fix corrupted or missing store paths by redownloading or rebuilding
     them. Note that this is slow because it requires computing a
     cryptographic hash of the contents of every path in the closure of
diff --git a/doc/manual/src/contributing/hacking.md b/doc/manual/src/contributing/hacking.md
index 90a8f1f94..59ce5cac7 100644
--- a/doc/manual/src/contributing/hacking.md
+++ b/doc/manual/src/contributing/hacking.md
@@ -71,18 +71,6 @@ To install it in `$(pwd)/outputs` and test it:
 nix (Nix) 3.0
 ```
 
-To run a functional test:
-
-```console
-make tests/test-name-should-auto-complete.sh.test
-```
-
-To run the unit-tests for C++ code:
-
-```
-make check
-```
-
 If you have a flakes-enabled Nix you can replace:
 
 ```console
@@ -94,3 +82,29 @@ by:
 ```console
 $ nix develop
 ```
+
+## Testing
+
+Nix comes with three different flavors of tests: unit, functional and integration.
+
+### Unit-tests
+
+The unit-tests for each Nix library (`libexpr`, `libstore`, etc..) are defined
+under `src/{library_name}/tests` using the
+[googletest](https://google.github.io/googletest/) framework.
+
+You can run the whole testsuite with `make check`, or the tests for a specific component with `make libfoo-tests_RUN`. Finer-grained filtering is also possible using the [--gtest_filter](https://google.github.io/googletest/advanced.html#running-a-subset-of-the-tests) command-line option.
+
+### Functional tests
+
+The functional tests reside under the `tests` directory and are listed in `tests/local.mk`.
+The whole testsuite can be run with `make install && make installcheck`.
+Individual tests can be run with `make tests/{testName}.sh.test`.
+
+### Integration tests
+
+The integration tests are defined in the Nix flake under the `hydraJobs.tests` attribute.
+These tests include everything that needs to interact with external services or run Nix in a non-trivial distributed setup.
+Because these tests are expensive and require more than what the standard github-actions setup provides, they only run on the master branch (on <https://hydra.nixos.org/jobset/nix/master>).
+
+You can run them manually with `nix build .#hydraJobs.tests.{testName}` or `nix-build -A hydraJobs.tests.{testName}`
diff --git a/doc/manual/src/expressions/arguments-variables.md b/doc/manual/src/expressions/arguments-variables.md
deleted file mode 100644
index 12198c879..000000000
--- a/doc/manual/src/expressions/arguments-variables.md
+++ /dev/null
@@ -1,80 +0,0 @@
-# Arguments and Variables
-
-The [Nix expression for GNU Hello](expression-syntax.md) is a
-function; it is missing some arguments that have to be filled in
-somewhere. In the Nix Packages collection this is done in the file
-`pkgs/top-level/all-packages.nix`, where all Nix expressions for
-packages are imported and called with the appropriate arguments. Here
-are some fragments of `all-packages.nix`, with annotations of what
-they mean:
-
-```nix
-...
-
-rec { ①
-
-  hello = import ../applications/misc/hello/ex-1 ② { ③
-    inherit fetchurl stdenv perl;
-  };
-
-  perl = import ../development/interpreters/perl { ④
-    inherit fetchurl stdenv;
-  };
-
-  fetchurl = import ../build-support/fetchurl {
-    inherit stdenv; ...
-  };
-
-  stdenv = ...;
-
-}
-```
-
-1.  This file defines a set of attributes, all of which are concrete
-    derivations (i.e., not functions). In fact, we define a *mutually
-    recursive* set of attributes. That is, the attributes can refer to
-    each other. This is precisely what we want since we want to “plug”
-    the various packages into each other.
-
-2.  Here we *import* the Nix expression for GNU Hello. The import
-    operation just loads and returns the specified Nix expression. In
-    fact, we could just have put the contents of the Nix expression
-    for GNU Hello in `all-packages.nix` at this point. That would be
-    completely equivalent, but it would make `all-packages.nix` rather
-    bulky.
-    
-    Note that we refer to `../applications/misc/hello/ex-1`, not
-    `../applications/misc/hello/ex-1/default.nix`. When you try to
-    import a directory, Nix automatically appends `/default.nix` to the
-    file name.
-
-3.  This is where the actual composition takes place. Here we *call* the
-    function imported from `../applications/misc/hello/ex-1` with a set
-    containing the things that the function expects, namely `fetchurl`,
-    `stdenv`, and `perl`. We use inherit again to use the attributes
-    defined in the surrounding scope (we could also have written
-    `fetchurl = fetchurl;`, etc.).
-    
-    The result of this function call is an actual derivation that can be
-    built by Nix (since when we fill in the arguments of the function,
-    what we get is its body, which is the call to `stdenv.mkDerivation`
-    in the [Nix expression for GNU Hello](expression-syntax.md)).
-    
-    > **Note**
-    > 
-    > Nixpkgs has a convenience function `callPackage` that imports and
-    > calls a function, filling in any missing arguments by passing the
-    > corresponding attribute from the Nixpkgs set, like this:
-    > 
-    > ```nix
-    > hello = callPackage ../applications/misc/hello/ex-1 { };
-    > ```
-    > 
-    > If necessary, you can set or override arguments:
-    > 
-    > ```nix
-    > hello = callPackage ../applications/misc/hello/ex-1 { stdenv = myStdenv; };
-    > ```
-
-4.  Likewise, we have to instantiate Perl, `fetchurl`, and the standard
-    environment.
diff --git a/doc/manual/src/expressions/build-script.md b/doc/manual/src/expressions/build-script.md
deleted file mode 100644
index b1eacae88..000000000
--- a/doc/manual/src/expressions/build-script.md
+++ /dev/null
@@ -1,70 +0,0 @@
-# Build Script
-
-Here is the builder referenced from Hello's Nix expression (stored in
-`pkgs/applications/misc/hello/ex-1/builder.sh`):
-
-```bash
-source $stdenv/setup ①
-
-PATH=$perl/bin:$PATH ②
-
-tar xvfz $src ③
-cd hello-*
-./configure --prefix=$out ④
-make ⑤
-make install
-```
-
-The builder can actually be made a lot shorter by using the *generic
-builder* functions provided by `stdenv`, but here we write out the build
-steps to elucidate what a builder does. It performs the following steps:
-
-1.  When Nix runs a builder, it initially completely clears the
-    environment (except for the attributes declared in the derivation).
-    This is done to prevent undeclared inputs from being used in the
-    build process. If for example the `PATH` contained `/usr/bin`, then
-    you might accidentally use `/usr/bin/gcc`.
-    
-    So the first step is to set up the environment. This is done by
-    calling the `setup` script of the standard environment. The
-    environment variable `stdenv` points to the location of the
-    standard environment being used. (It wasn't specified explicitly
-    as an attribute in Hello's Nix expression, but `mkDerivation` adds
-    it automatically.)
-
-2.  Since Hello needs Perl, we have to make sure that Perl is in the
-    `PATH`. The `perl` environment variable points to the location of
-    the Perl package (since it was passed in as an attribute to the
-    derivation), so `$perl/bin` is the directory containing the Perl
-    interpreter.
-
-3.  Now we have to unpack the sources. The `src` attribute was bound to
-    the result of fetching the Hello source tarball from the network, so
-    the `src` environment variable points to the location in the Nix
-    store to which the tarball was downloaded. After unpacking, we `cd`
-    to the resulting source directory.
-    
-    The whole build is performed in a temporary directory created in
-    `/tmp`, by the way. This directory is removed after the builder
-    finishes, so there is no need to clean up the sources afterwards.
-    Also, the temporary directory is always newly created, so you don't
-    have to worry about files from previous builds interfering with the
-    current build.
-
-4.  GNU Hello is a typical Autoconf-based package, so we first have to
-    run its `configure` script. In Nix every package is stored in a
-    separate location in the Nix store, for instance
-    `/nix/store/9a54ba97fb71b65fda531012d0443ce2-hello-2.1.1`. Nix
-    computes this path by cryptographically hashing all attributes of
-    the derivation. The path is passed to the builder through the `out`
-    environment variable. So here we give `configure` the parameter
-    `--prefix=$out` to cause Hello to be installed in the expected
-    location.
-
-5.  Finally we build Hello (`make`) and install it into the location
-    specified by `out` (`make install`).
-
-If you are wondering about the absence of error checking on the result
-of various commands called in the builder: this is because the shell
-script is evaluated with Bash's `-e` option, which causes the script to
-be aborted if any command fails without an error check.
diff --git a/doc/manual/src/expressions/expression-language.md b/doc/manual/src/expressions/expression-language.md
deleted file mode 100644
index 267fcb983..000000000
--- a/doc/manual/src/expressions/expression-language.md
+++ /dev/null
@@ -1,12 +0,0 @@
-# Nix Expression Language
-
-The Nix expression language is a pure, lazy, functional language. Purity
-means that operations in the language don't have side-effects (for
-instance, there is no variable assignment). Laziness means that
-arguments to functions are evaluated only when they are needed.
-Functional means that functions are “normal” values that can be passed
-around and manipulated in interesting ways. The language is not a
-full-featured, general purpose language. Its main job is to describe
-packages, compositions of packages, and the variability within packages.
-
-This section presents the various features of the language.
diff --git a/doc/manual/src/expressions/expression-syntax.md b/doc/manual/src/expressions/expression-syntax.md
deleted file mode 100644
index 6b93e692c..000000000
--- a/doc/manual/src/expressions/expression-syntax.md
+++ /dev/null
@@ -1,93 +0,0 @@
-# Expression Syntax
-
-Here is a Nix expression for GNU Hello:
-
-```nix
-{ stdenv, fetchurl, perl }: ①
-
-stdenv.mkDerivation { ②
-  name = "hello-2.1.1"; ③
-  builder = ./builder.sh; ④
-  src = fetchurl { ⑤
-    url = "ftp://ftp.nluug.nl/pub/gnu/hello/hello-2.1.1.tar.gz";
-    sha256 = "1md7jsfd8pa45z73bz1kszpp01yw6x5ljkjk2hx7wl800any6465";
-  };
-  inherit perl; ⑥
-}
-```
-
-This file is actually already in the Nix Packages collection in
-`pkgs/applications/misc/hello/ex-1/default.nix`. It is customary to
-place each package in a separate directory and call the single Nix
-expression in that directory `default.nix`. The file has the following
-elements (referenced from the figure by number):
-
-1.  This states that the expression is a *function* that expects to be
-    called with three arguments: `stdenv`, `fetchurl`, and `perl`. They
-    are needed to build Hello, but we don't know how to build them here;
-    that's why they are function arguments. `stdenv` is a package that
-    is used by almost all Nix Packages; it provides a
-    “standard” environment consisting of the things you would expect
-    in a basic Unix environment: a C/C++ compiler (GCC, to be precise),
-    the Bash shell, fundamental Unix tools such as `cp`, `grep`, `tar`,
-    etc. `fetchurl` is a function that downloads files. `perl` is the
-    Perl interpreter.
-    
-    Nix functions generally have the form `{ x, y, ..., z }: e` where
-    `x`, `y`, etc. are the names of the expected arguments, and where
-    *e* is the body of the function. So here, the entire remainder of
-    the file is the body of the function; when given the required
-    arguments, the body should describe how to build an instance of
-    the Hello package.
-
-2.  So we have to build a package. Building something from other stuff
-    is called a *derivation* in Nix (as opposed to sources, which are
-    built by humans instead of computers). We perform a derivation by
-    calling `stdenv.mkDerivation`. `mkDerivation` is a function
-    provided by `stdenv` that builds a package from a set of
-    *attributes*. A set is just a list of key/value pairs where each
-    key is a string and each value is an arbitrary Nix
-    expression. They take the general form `{ name1 = expr1; ...
-    nameN = exprN; }`.
-
-3.  The attribute `name` specifies the symbolic name and version of
-    the package. Nix doesn't really care about these things, but they
-    are used by for instance `nix-env -q` to show a “human-readable”
-    name for packages. This attribute is required by `mkDerivation`.
-
-4.  The attribute `builder` specifies the builder. This attribute can
-    sometimes be omitted, in which case `mkDerivation` will fill in a
-    default builder (which does a `configure; make; make install`, in
-    essence). Hello is sufficiently simple that the default builder
-    would suffice, but in this case, we will show an actual builder
-    for educational purposes. The value `./builder.sh` refers to the
-    shell script shown in the [next section](build-script.md),
-    discussed below.
-
-5.  The builder has to know what the sources of the package are. Here,
-    the attribute `src` is bound to the result of a call to the
-    `fetchurl` function. Given a URL and a SHA-256 hash of the expected
-    contents of the file at that URL, this function builds a derivation
-    that downloads the file and checks its hash. So the sources are a
-    dependency that like all other dependencies is built before Hello
-    itself is built.
-    
-    Instead of `src` any other name could have been used, and in fact
-    there can be any number of sources (bound to different attributes).
-    However, `src` is customary, and it's also expected by the default
-    builder (which we don't use in this example).
-
-6.  Since the derivation requires Perl, we have to pass the value of the
-    `perl` function argument to the builder. All attributes in the set
-    are actually passed as environment variables to the builder, so
-    declaring an attribute
-
-    ```nix
-    perl = perl;
-    ```
-    
-    will do the trick: it binds an attribute `perl` to the function
-    argument which also happens to be called `perl`. However, it looks a
-    bit silly, so there is a shorter syntax. The `inherit` keyword
-    causes the specified attributes to be bound to whatever variables
-    with the same name happen to be in scope.
diff --git a/doc/manual/src/expressions/generic-builder.md b/doc/manual/src/expressions/generic-builder.md
deleted file mode 100644
index cf26b5f82..000000000
--- a/doc/manual/src/expressions/generic-builder.md
+++ /dev/null
@@ -1,66 +0,0 @@
-# Generic Builder Syntax
-
-Recall that the [build script for GNU Hello](build-script.md) looked
-something like this:
-
-```bash
-PATH=$perl/bin:$PATH
-tar xvfz $src
-cd hello-*
-./configure --prefix=$out
-make
-make install
-```
-
-The builders for almost all Unix packages look like this — set up some
-environment variables, unpack the sources, configure, build, and
-install. For this reason the standard environment provides some Bash
-functions that automate the build process. Here is what a builder using
-the generic build facilities looks like:
-
-```bash
-buildInputs="$perl" ①
-
-source $stdenv/setup ②
-
-genericBuild ③
-```
-
-Here is what each line means:
-
-1.  The `buildInputs` variable tells `setup` to use the indicated
-    packages as “inputs”. This means that if a package provides a `bin`
-    subdirectory, it's added to `PATH`; if it has a `include`
-    subdirectory, it's added to GCC's header search path; and so on.
-    (This is implemented in a modular way: `setup` tries to source the
-    file `pkg/nix-support/setup-hook` of all dependencies. These “setup
-    hooks” can then set up whatever environment variables they want; for
-    instance, the setup hook for Perl sets the `PERL5LIB` environment
-    variable to contain the `lib/site_perl` directories of all inputs.)
-
-2.  The function `genericBuild` is defined in the file `$stdenv/setup`.
-
-3.  The final step calls the shell function `genericBuild`, which
-    performs the steps that were done explicitly in the previous build
-    script. The generic builder is smart enough to figure out whether
-    to unpack the sources using `gzip`, `bzip2`, etc.  It can be
-    customised in many ways; see the Nixpkgs manual for details.
-
-Discerning readers will note that the `buildInputs` could just as well
-have been set in the Nix expression, like this:
-
-```nix
-  buildInputs = [ perl ];
-```
-
-The `perl` attribute can then be removed, and the builder becomes even
-shorter:
-
-```bash
-source $stdenv/setup
-genericBuild
-```
-
-In fact, `mkDerivation` provides a default builder that looks exactly
-like that, so it is actually possible to omit the builder for Hello
-entirely.
diff --git a/doc/manual/src/expressions/language-values.md b/doc/manual/src/expressions/language-values.md
deleted file mode 100644
index 75ae9f2eb..000000000
--- a/doc/manual/src/expressions/language-values.md
+++ /dev/null
@@ -1,251 +0,0 @@
-# Values
-
-## Simple Values
-
-Nix has the following basic data types:
-
-  - *Strings* can be written in three ways.
-    
-    The most common way is to enclose the string between double quotes,
-    e.g., `"foo bar"`. Strings can span multiple lines. The special
-    characters `"` and `\` and the character sequence `${` must be
-    escaped by prefixing them with a backslash (`\`). Newlines, carriage
-    returns and tabs can be written as `\n`, `\r` and `\t`,
-    respectively.
-    
-    You can include the result of an expression into a string by
-    enclosing it in `${...}`, a feature known as *antiquotation*. The
-    enclosed expression must evaluate to something that can be coerced
-    into a string (meaning that it must be a string, a path, or a
-    derivation). For instance, rather than writing
-    
-    ```nix
-    "--with-freetype2-library=" + freetype + "/lib"
-    ```
-    
-    (where `freetype` is a derivation), you can instead write the more
-    natural
-    
-    ```nix
-    "--with-freetype2-library=${freetype}/lib"
-    ```
-    
-    The latter is automatically translated to the former. A more
-    complicated example (from the Nix expression for
-    [Qt](http://www.trolltech.com/products/qt)):
-    
-    ```nix
-    configureFlags = "
-      -system-zlib -system-libpng -system-libjpeg
-      ${if openglSupport then "-dlopen-opengl
-        -L${mesa}/lib -I${mesa}/include
-        -L${libXmu}/lib -I${libXmu}/include" else ""}
-      ${if threadSupport then "-thread" else "-no-thread"}
-    ";
-    ```
-    
-    Note that Nix expressions and strings can be arbitrarily nested; in
-    this case the outer string contains various antiquotations that
-    themselves contain strings (e.g., `"-thread"`), some of which in
-    turn contain expressions (e.g., `${mesa}`).
-    
-    The second way to write string literals is as an *indented string*,
-    which is enclosed between pairs of *double single-quotes*, like so:
-    
-    ```nix
-    ''
-      This is the first line.
-      This is the second line.
-        This is the third line.
-    ''
-    ```
-    
-    This kind of string literal intelligently strips indentation from
-    the start of each line. To be precise, it strips from each line a
-    number of spaces equal to the minimal indentation of the string as a
-    whole (disregarding the indentation of empty lines). For instance,
-    the first and second line are indented two spaces, while the third
-    line is indented four spaces. Thus, two spaces are stripped from
-    each line, so the resulting string is
-    
-    ```nix
-    "This is the first line.\nThis is the second line.\n  This is the third line.\n"
-    ```
-    
-    Note that the whitespace and newline following the opening `''` is
-    ignored if there is no non-whitespace text on the initial line.
-    
-    Antiquotation (`${expr}`) is supported in indented strings.
-    
-    Since `${` and `''` have special meaning in indented strings, you
-    need a way to quote them. `$` can be escaped by prefixing it with
-    `''` (that is, two single quotes), i.e., `''$`. `''` can be escaped
-    by prefixing it with `'`, i.e., `'''`. `$` removes any special
-    meaning from the following `$`. Linefeed, carriage-return and tab
-    characters can be written as `''\n`, `''\r`, `''\t`, and `''\`
-    escapes any other character.
-    
-    Indented strings are primarily useful in that they allow multi-line
-    string literals to follow the indentation of the enclosing Nix
-    expression, and that less escaping is typically necessary for
-    strings representing languages such as shell scripts and
-    configuration files because `''` is much less common than `"`.
-    Example:
-    
-    ```nix
-    stdenv.mkDerivation {
-      ...
-      postInstall =
-        ''
-          mkdir $out/bin $out/etc
-          cp foo $out/bin
-          echo "Hello World" > $out/etc/foo.conf
-          ${if enableBar then "cp bar $out/bin" else ""}
-        '';
-      ...
-    }
-    ```
-    
-    Finally, as a convenience, *URIs* as defined in appendix B of
-    [RFC 2396](http://www.ietf.org/rfc/rfc2396.txt) can be written *as
-    is*, without quotes. For instance, the string
-    `"http://example.org/foo.tar.bz2"` can also be written as
-    `http://example.org/foo.tar.bz2`.
-
-  - Numbers, which can be *integers* (like `123`) or *floating point*
-    (like `123.43` or `.27e13`).
-    
-    Numbers are type-compatible: pure integer operations will always
-    return integers, whereas any operation involving at least one
-    floating point number will have a floating point number as a result.
-
-  - *Paths*, e.g., `/bin/sh` or `./builder.sh`. A path must contain at
-    least one slash to be recognised as such. For instance, `builder.sh`
-    is not a path: it's parsed as an expression that selects the
-    attribute `sh` from the variable `builder`. If the file name is
-    relative, i.e., if it does not begin with a slash, it is made
-    absolute at parse time relative to the directory of the Nix
-    expression that contained it. For instance, if a Nix expression in
-    `/foo/bar/bla.nix` refers to `../xyzzy/fnord.nix`, the absolute path
-    is `/foo/xyzzy/fnord.nix`.
-    
-    If the first component of a path is a `~`, it is interpreted as if
-    the rest of the path were relative to the user's home directory.
-    e.g. `~/foo` would be equivalent to `/home/edolstra/foo` for a user
-    whose home directory is `/home/edolstra`.
-    
-    Paths can also be specified between angle brackets, e.g.
-    `<nixpkgs>`. This means that the directories listed in the
-    environment variable `NIX_PATH` will be searched for the given file
-    or directory name.
-
-    Antiquotation is supported in any paths except those in angle brackets.
-    `./${foo}-${bar}.nix` is a more convenient way of writing 
-    `./. + "/" + foo + "-" + bar + ".nix"` or `./. + "/${foo}-${bar}.nix"`. At
-    least one slash must appear *before* any antiquotations for this to be
-    recognized as a path. `a.${foo}/b.${bar}` is a syntactically valid division
-    operation. `./a.${foo}/b.${bar}` is a path.
-
-  - *Booleans* with values `true` and `false`.
-
-  - The null value, denoted as `null`.
-
-## Lists
-
-Lists are formed by enclosing a whitespace-separated list of values
-between square brackets. For example,
-
-```nix
-[ 123 ./foo.nix "abc" (f { x = y; }) ]
-```
-
-defines a list of four elements, the last being the result of a call to
-the function `f`. Note that function calls have to be enclosed in
-parentheses. If they had been omitted, e.g.,
-
-```nix
-[ 123 ./foo.nix "abc" f { x = y; } ]
-```
-
-the result would be a list of five elements, the fourth one being a
-function and the fifth being a set.
-
-Note that lists are only lazy in values, and they are strict in length.
-
-## Sets
-
-Sets are really the core of the language, since ultimately the Nix
-language is all about creating derivations, which are really just sets
-of attributes to be passed to build scripts.
-
-Sets are just a list of name/value pairs (called *attributes*) enclosed
-in curly brackets, where each value is an arbitrary expression
-terminated by a semicolon. For example:
-
-```nix
-{ x = 123;
-  text = "Hello";
-  y = f { bla = 456; };
-}
-```
-
-This defines a set with attributes named `x`, `text`, `y`. The order of
-the attributes is irrelevant. An attribute name may only occur once.
-
-Attributes can be selected from a set using the `.` operator. For
-instance,
-
-```nix
-{ a = "Foo"; b = "Bar"; }.a
-```
-
-evaluates to `"Foo"`. It is possible to provide a default value in an
-attribute selection using the `or` keyword. For example,
-
-```nix
-{ a = "Foo"; b = "Bar"; }.c or "Xyzzy"
-```
-
-will evaluate to `"Xyzzy"` because there is no `c` attribute in the set.
-
-You can use arbitrary double-quoted strings as attribute names:
-
-```nix
-{ "foo ${bar}" = 123; "nix-1.0" = 456; }."foo ${bar}"
-```
-
-This will evaluate to `123` (Assuming `bar` is antiquotable). In the
-case where an attribute name is just a single antiquotation, the quotes
-can be dropped:
-
-```nix
-{ foo = 123; }.${bar} or 456
-```
-
-This will evaluate to `123` if `bar` evaluates to `"foo"` when coerced
-to a string and `456` otherwise (again assuming `bar` is antiquotable).
-
-In the special case where an attribute name inside of a set declaration
-evaluates to `null` (which is normally an error, as `null` is not
-antiquotable), that attribute is simply not added to the set:
-
-```nix
-{ ${if foo then "bar" else null} = true; }
-```
-
-This will evaluate to `{}` if `foo` evaluates to `false`.
-
-A set that has a `__functor` attribute whose value is callable (i.e. is
-itself a function or a set with a `__functor` attribute whose value is
-callable) can be applied as if it were a function, with the set itself
-passed in first , e.g.,
-
-```nix
-let add = { __functor = self: x: x + self.x; };
-    inc = add // { x = 1; };
-in inc 1
-```
-
-evaluates to `2`. This can be used to attach metadata to a function
-without the caller needing to treat it specially, or to implement a form
-of object-oriented programming, for example.
diff --git a/doc/manual/src/expressions/simple-building-testing.md b/doc/manual/src/expressions/simple-building-testing.md
deleted file mode 100644
index 7f0d8f841..000000000
--- a/doc/manual/src/expressions/simple-building-testing.md
+++ /dev/null
@@ -1,61 +0,0 @@
-# Building and Testing
-
-You can now try to build Hello. Of course, you could do `nix-env -f . -iA
-hello`, but you may not want to install a possibly broken package just
-yet. The best way to test the package is by using the command
-`nix-build`, which builds a Nix expression and creates a symlink named
-`result` in the current directory:
-
-```console
-$ nix-build -A hello
-building path `/nix/store/632d2b22514d...-hello-2.1.1'
-hello-2.1.1/
-hello-2.1.1/intl/
-hello-2.1.1/intl/ChangeLog
-...
-
-$ ls -l result
-lrwxrwxrwx ... 2006-09-29 10:43 result -> /nix/store/632d2b22514d...-hello-2.1.1
-
-$ ./result/bin/hello
-Hello, world!
-```
-
-The `-A` option selects the `hello` attribute. This is faster than
-using the symbolic package name specified by the `name` attribute
-(which also happens to be `hello`) and is unambiguous (there can be
-multiple packages with the symbolic name `hello`, but there can be
-only one attribute in a set named `hello`).
-
-`nix-build` registers the `./result` symlink as a garbage collection
-root, so unless and until you delete the `./result` symlink, the output
-of the build will be safely kept on your system. You can use
-`nix-build`’s `-o` switch to give the symlink another name.
-
-Nix has transactional semantics. Once a build finishes successfully, Nix
-makes a note of this in its database: it registers that the path denoted
-by `out` is now “valid”. If you try to build the derivation again, Nix
-will see that the path is already valid and finish immediately. If a
-build fails, either because it returns a non-zero exit code, because Nix
-or the builder are killed, or because the machine crashes, then the
-output paths will not be registered as valid. If you try to build the
-derivation again, Nix will remove the output paths if they exist (e.g.,
-because the builder died half-way through `make
-install`) and try again. Note that there is no “negative caching”: Nix
-doesn't remember that a build failed, and so a failed build can always
-be repeated. This is because Nix cannot distinguish between permanent
-failures (e.g., a compiler error due to a syntax error in the source)
-and transient failures (e.g., a disk full condition).
-
-Nix also performs locking. If you run multiple Nix builds
-simultaneously, and they try to build the same derivation, the first Nix
-instance that gets there will perform the build, while the others block
-(or perform other derivations if available) until the build finishes:
-
-```console
-$ nix-build -A hello
-waiting for lock on `/nix/store/0h5b7hp8d4hqfrw8igvx97x1xawrjnac-hello-2.1.1x'
-```
-
-So it is always safe to run multiple instances of Nix in parallel (which
-isn’t the case with, say, `make`).
diff --git a/doc/manual/src/expressions/simple-expression.md b/doc/manual/src/expressions/simple-expression.md
deleted file mode 100644
index 857f71b9b..000000000
--- a/doc/manual/src/expressions/simple-expression.md
+++ /dev/null
@@ -1,23 +0,0 @@
-# A Simple Nix Expression
-
-This section shows how to add and test the [GNU Hello
-package](http://www.gnu.org/software/hello/hello.html) to the Nix
-Packages collection. Hello is a program that prints out the text “Hello,
-world\!”.
-
-To add a package to the Nix Packages collection, you generally need to
-do three things:
-
-1.  Write a Nix expression for the package. This is a file that
-    describes all the inputs involved in building the package, such as
-    dependencies, sources, and so on.
-
-2.  Write a *builder*. This is a shell script that builds the package
-    from the inputs. (In fact, it can be written in any language, but
-    typically it's a `bash` shell script.)
-
-3.  Add the package to the file `pkgs/top-level/all-packages.nix`. The
-    Nix expression written in the first step is a *function*; it
-    requires other packages in order to build it. In this step you put
-    it all together, i.e., you call the function with the right
-    arguments to build the actual package.
diff --git a/doc/manual/src/expressions/writing-nix-expressions.md b/doc/manual/src/expressions/writing-nix-expressions.md
deleted file mode 100644
index 5664108e7..000000000
--- a/doc/manual/src/expressions/writing-nix-expressions.md
+++ /dev/null
@@ -1,12 +0,0 @@
-This chapter shows you how to write Nix expressions, which instruct Nix
-how to build packages. It starts with a simple example (a Nix expression
-for GNU Hello), and then moves on to a more in-depth look at the Nix
-expression language.
-
-> **Note**
-> 
-> This chapter is mostly about the Nix expression language. For more
-> extensive information on adding packages to the Nix Packages
-> collection (such as functions in the standard environment and coding
-> conventions), please consult [its
-> manual](http://nixos.org/nixpkgs/manual/).
diff --git a/doc/manual/src/glossary.md b/doc/manual/src/glossary.md
index 71ff13275..aa0ac78cb 100644
--- a/doc/manual/src/glossary.md
+++ b/doc/manual/src/glossary.md
@@ -1,48 +1,48 @@
 # Glossary
 
-  - derivation\
+  - [derivation]{#gloss-derivation}\
     A description of a build action. The result of a derivation is a
     store object. Derivations are typically specified in Nix expressions
-    using the [`derivation` primitive](expressions/derivations.md). These are
+    using the [`derivation` primitive](language/derivations.md). These are
     translated into low-level *store derivations* (implicitly by
     `nix-env` and `nix-build`, or explicitly by `nix-instantiate`).
 
-  - store\
+  - [store]{#gloss-store}\
     The location in the file system where store objects live. Typically
     `/nix/store`.
 
-  - store path\
+  - [store path]{#gloss-store-path}\
     The location in the file system of a store object, i.e., an
     immediate child of the Nix store directory.
 
-  - store object\
+  - [store object]{#gloss-store-object}\
     A file that is an immediate child of the Nix store directory. These
     can be regular files, but also entire directory trees. Store objects
     can be sources (objects copied from outside of the store),
     derivation outputs (objects produced by running a build action), or
     derivations (files describing a build action).
 
-  - substitute\
+  - [substitute]{#gloss-substitute}\
     A substitute is a command invocation stored in the Nix database that
     describes how to build a store object, bypassing the normal build
     mechanism (i.e., derivations). Typically, the substitute builds the
     store object by downloading a pre-built version of the store object
     from some server.
 
-  - purity\
+  - [purity]{#gloss-purity}\
     The assumption that equal Nix derivations when run always produce
     the same output. This cannot be guaranteed in general (e.g., a
     builder can rely on external inputs such as the network or the
     system time) but the Nix model assumes it.
 
-  - Nix expression\
+  - [Nix expression]{#gloss-nix-expression}\
     A high-level description of software packages and compositions
     thereof. Deploying software using Nix entails writing Nix
     expressions for your packages. Nix expressions are translated to
     derivations that are stored in the Nix store. These derivations can
     then be built.
 
-  - reference\
+  - [reference]{#gloss-reference}\
     A store path `P` is said to have a reference to a store path `Q` if
     the store object at `P` contains the path `Q` somewhere. The
     *references* of a store path are the set of store paths to which it
@@ -52,11 +52,11 @@
     output paths), whereas an output path only references other output
     paths.
 
-  - reachable\
+  - [reachable]{#gloss-reachable}\
     A store path `Q` is reachable from another store path `P` if `Q`
     is in the *closure* of the *references* relation.
 
-  - closure\
+  - [closure]{#gloss-closure}\
     The closure of a store path is the set of store paths that are
     directly or indirectly “reachable” from that store path; that is,
     it’s the closure of the path under the *references* relation. For
@@ -71,34 +71,34 @@
     to path `Q`, then `Q` is in the closure of `P`. Further, if `Q`
     references `R` then `R` is also in the closure of `P`.
 
-  - output path\
+  - [output path]{#gloss-output-path}\
     A store path produced by a derivation.
 
-  - deriver\
+  - [deriver]{#gloss-deriver}\
     The deriver of an *output path* is the store
     derivation that built it.
 
-  - validity\
+  - [validity]{#gloss-validity}\
     A store path is considered *valid* if it exists in the file system,
     is listed in the Nix database as being valid, and if all paths in
     its closure are also valid.
 
-  - user environment\
+  - [user environment]{#gloss-user-env}\
     An automatically generated store object that consists of a set of
     symlinks to “active” applications, i.e., other store paths. These
     are generated automatically by
     [`nix-env`](command-ref/nix-env.md). See *profiles*.
 
-  - profile\
+  - [profile]{#gloss-profile}\
     A symlink to the current *user environment* of a user, e.g.,
     `/nix/var/nix/profiles/default`.
 
-  - NAR\
+  - [NAR]{#gloss-nar}\
     A *N*ix *AR*chive. This is a serialisation of a path in the Nix
     store. It can contain regular files, directories and symbolic
     links.  NARs are generated and unpacked using `nix-store --dump`
     and `nix-store --restore`.
-  - `∅` \
+  - [`∅`]{#gloss-emtpy-set}\
     The empty set symbol. In the context of profile history, this denotes a package is not present in a particular version of the profile.
-  - `ε` \
+  - [`ε`]{#gloss-epsilon}\
     The epsilon symbol. In the context of a package, this means the version is empty. More precisely, the derivation does not have a version attribute.
diff --git a/doc/manual/src/installation/installing-binary.md b/doc/manual/src/installation/installing-binary.md
index e5fb50088..2d007ca1b 100644
--- a/doc/manual/src/installation/installing-binary.md
+++ b/doc/manual/src/installation/installing-binary.md
@@ -13,7 +13,7 @@ for your platform:
 - multi-user on macOS
 
   > **Notes on read-only filesystem root in macOS 10.15 Catalina +**
-  > 
+  >
   > - It took some time to support this cleanly. You may see posts,
   >   examples, and tutorials using obsolete workarounds.
   > - Supporting it cleanly made macOS installs too complex to qualify
@@ -31,8 +31,8 @@ $ sh <(curl -L https://nixos.org/nix/install) --no-daemon
 ```
 
 This will perform a single-user installation of Nix, meaning that `/nix`
-is owned by the invoking user. You should run this under your usual user
-account, *not* as root. The script will invoke `sudo` to create `/nix`
+is owned by the invoking user. You can run this under your usual user
+account or root. The script will invoke `sudo` to create `/nix`
 if it doesn’t already exist. If you don’t have `sudo`, you should
 manually create `/nix` first as root, e.g.:
 
@@ -71,11 +71,11 @@ $ sh <(curl -L https://nixos.org/nix/install) --daemon
 
 The multi-user installation of Nix will create build users between the
 user IDs 30001 and 30032, and a group with the group ID 30000. You
-should run this under your usual user account, *not* as root. The script
+can run this under your usual user account or root. The script
 will invoke `sudo` as needed.
 
 > **Note**
-> 
+>
 > If you need Nix to use a different group ID or user ID set, you will
 > have to download the tarball manually and [edit the install
 > script](#installing-from-a-binary-tarball).
@@ -148,7 +148,8 @@ and `/etc/zshrc` which you may remove.
    This will remove all the build users that no longer serve a purpose.
 
 4. Edit fstab using `sudo vifs` to remove the line mounting the Nix Store
-   volume on `/nix`, which looks like this,
+   volume on `/nix`, which looks like
+   `UUID=<uuid> /nix apfs rw,noauto,nobrowse,suid,owners` or
    `LABEL=Nix\040Store /nix apfs rw,nobrowse`. This will prevent automatic
    mounting of the Nix Store volume.
 
@@ -167,7 +168,7 @@ and `/etc/zshrc` which you may remove.
    removed next.
 
 7. Remove the Nix Store volume:
-   
+
    ```console
    sudo diskutil apfs deleteVolume /nix
    ```
@@ -175,8 +176,20 @@ and `/etc/zshrc` which you may remove.
    This will remove the Nix Store volume and everything that was added to the
    store.
 
+   If the output indicates that the command couldn't remove the volume, you should
+   make sure you don't have an _unmounted_ Nix Store volume. Look for a
+   "Nix Store" volume in the output of the following command:
+
+   ```console
+   diskutil list
+   ```
+
+   If you _do_ see a "Nix Store" volume, delete it by re-running the diskutil
+   deleteVolume command, but replace `/nix` with the store volume's `diskXsY`
+   identifier.
+
 > **Note**
-> 
+>
 > After you complete the steps here, you will still have an empty `/nix`
 > directory. This is an expected sign of a successful uninstall. The empty
 > `/nix` directory will disappear the next time you reboot.
@@ -186,12 +199,12 @@ and `/etc/zshrc` which you may remove.
 > read-only root will prevent you from manually deleting the empty `/nix`
 > mountpoint.
 
-# macOS Installation <a name="sect-macos-installation-change-store-prefix"></a><a name="sect-macos-installation-encrypted-volume"></a><a name="sect-macos-installation-symlink"></a><a name="sect-macos-installation-recommended-notes"></a>
+# macOS Installation
+[]{#sect-macos-installation-change-store-prefix}[]{#sect-macos-installation-encrypted-volume}[]{#sect-macos-installation-symlink}[]{#sect-macos-installation-recommended-notes}
 <!-- Note: anchors above to catch permalinks to old explanations -->
 
 We believe we have ironed out how to cleanly support the read-only root
-on modern macOS. New installs will do this automatically, and you can
-also re-run a new installer to convert your existing setup.
+on modern macOS. New installs will do this automatically.
 
 This section previously detailed the situation, options, and trade-offs,
 but it now only outlines what the installer does. You don't need to know
diff --git a/doc/manual/src/expressions/advanced-attributes.md b/doc/manual/src/language/advanced-attributes.md
index 000595815..2e7e80ed0 100644
--- a/doc/manual/src/expressions/advanced-attributes.md
+++ b/doc/manual/src/language/advanced-attributes.md
@@ -2,7 +2,7 @@
 
 Derivations can declare some infrequently used optional attributes.
 
-  - `allowedReferences`\
+  - [`allowedReferences`]{#adv-attr-allowedReferences}\
     The optional attribute `allowedReferences` specifies a list of legal
     references (dependencies) of the output of the builder. For example,
 
@@ -17,7 +17,7 @@ Derivations can declare some infrequently used optional attributes.
     booting Linux don’t have accidental dependencies on other paths in
     the Nix store.
 
-  - `allowedRequisites`\
+  - [`allowedRequisites`]{#adv-attr-allowedRequisites}\
     This attribute is similar to `allowedReferences`, but it specifies
     the legal requisites of the whole closure, so all the dependencies
     recursively. For example,
@@ -30,7 +30,7 @@ Derivations can declare some infrequently used optional attributes.
     runtime dependency than `foobar`, and in addition it enforces that
     `foobar` itself doesn't introduce any other dependency itself.
 
-  - `disallowedReferences`\
+  - [`disallowedReferences`]{#adv-attr-disallowedReferences}\
     The optional attribute `disallowedReferences` specifies a list of
     illegal references (dependencies) of the output of the builder. For
     example,
@@ -42,7 +42,7 @@ Derivations can declare some infrequently used optional attributes.
     enforces that the output of a derivation cannot have a direct
     runtime dependencies on the derivation `foo`.
 
-  - `disallowedRequisites`\
+  - [`disallowedRequisites`]{#adv-attr-disallowedRequisites}\
     This attribute is similar to `disallowedReferences`, but it
     specifies illegal requisites for the whole closure, so all the
     dependencies recursively. For example,
@@ -55,7 +55,7 @@ Derivations can declare some infrequently used optional attributes.
     dependency on `foobar` or any other derivation depending recursively
     on `foobar`.
 
-  - `exportReferencesGraph`\
+  - [`exportReferencesGraph`]{#adv-attr-exportReferencesGraph}\
     This attribute allows builders access to the references graph of
     their inputs. The attribute is a list of inputs in the Nix store
     whose references graph the builder needs to know. The value of
@@ -84,7 +84,7 @@ Derivations can declare some infrequently used optional attributes.
     with a Nix store containing the closure of a bootable NixOS
     configuration).
 
-  - `impureEnvVars`\
+  - [`impureEnvVars`]{#adv-attr-impureEnvVars}\
     This attribute allows you to specify a list of environment variables
     that should be passed from the environment of the calling user to
     the builder. Usually, the environment is cleared completely when the
@@ -112,7 +112,7 @@ Derivations can declare some infrequently used optional attributes.
     > environmental variables come from the environment of the
     > `nix-build`.
 
-  - `outputHash`; `outputHashAlgo`; `outputHashMode`\
+  - [`outputHash`]{#adv-attr-outputHash}; [`outputHashAlgo`]{#adv-attr-outputHashAlgo}; [`outputHashMode`]{#adv-attr-outputHashMode}\
     These attributes declare that the derivation is a so-called
     *fixed-output derivation*, which means that a cryptographic hash of
     the output is already known in advance. When the build of a
@@ -208,7 +208,7 @@ Derivations can declare some infrequently used optional attributes.
     [`nix-hash` command](../command-ref/nix-hash.md) for information
     about converting to and from base-32 notation.)
     
-  - `__contentAddressed`
+  - [`__contentAddressed`]{#adv-attr-__contentAddressed}
     If this **experimental** attribute is set to true, then the derivation
     outputs will be stored in a content-addressed location rather than the
     traditional input-addressed one.
@@ -216,7 +216,7 @@ Derivations can declare some infrequently used optional attributes.
     
     Setting this attribute also requires setting `outputHashMode` and `outputHashAlgo` like for *fixed-output derivations* (see above).
 
-  - `passAsFile`\
+  - [`passAsFile`]{#adv-attr-passAsFile}\
     A list of names of attributes that should be passed via files rather
     than environment variables. For example, if you have
 
@@ -234,7 +234,7 @@ Derivations can declare some infrequently used optional attributes.
     builder, since most operating systems impose a limit on the size
     of the environment (typically, a few hundred kilobyte).
 
-  - `preferLocalBuild`\
+  - [`preferLocalBuild`]{#adv-attr-preferLocalBuild}\
     If this attribute is set to `true` and [distributed building is
     enabled](../advanced-topics/distributed-builds.md), then, if
     possible, the derivation will be built locally instead of forwarded
@@ -242,7 +242,7 @@ Derivations can declare some infrequently used optional attributes.
     where the cost of doing a download or remote build would exceed
     the cost of building locally.
 
-  - `allowSubstitutes`\
+  - [`allowSubstitutes`]{#adv-attr-allowSubstitutes}\
     If this attribute is set to `false`, then Nix will always build this
     derivation; it will not try to substitute its outputs. This is
     useful for very trivial derivations (such as `writeText` in Nixpkgs)
diff --git a/doc/manual/src/expressions/builtin-constants.md b/doc/manual/src/language/builtin-constants.md
index 1404289e5..78d066a82 100644
--- a/doc/manual/src/expressions/builtin-constants.md
+++ b/doc/manual/src/language/builtin-constants.md
@@ -14,7 +14,7 @@ Here are the constants built into the Nix expression evaluator:
     This allows a Nix expression to fall back gracefully on older Nix
     installations that don’t have the desired built-in function.
 
-  - `builtins.currentSystem`\
+  - [`builtins.currentSystem`]{#builtins-currentSystem}\
     The built-in value `currentSystem` evaluates to the Nix platform
     identifier for the Nix installation on which the expression is being
     evaluated, such as `"i686-linux"` or `"x86_64-darwin"`.
diff --git a/doc/manual/src/expressions/builtins-prefix.md b/doc/manual/src/language/builtins-prefix.md
index c631a8453..c631a8453 100644
--- a/doc/manual/src/expressions/builtins-prefix.md
+++ b/doc/manual/src/language/builtins-prefix.md
diff --git a/doc/manual/src/expressions/builtins-suffix.md b/doc/manual/src/language/builtins-suffix.md
index a74db2857..a74db2857 100644
--- a/doc/manual/src/expressions/builtins-suffix.md
+++ b/doc/manual/src/language/builtins-suffix.md
diff --git a/doc/manual/src/expressions/language-constructs.md b/doc/manual/src/language/constructs.md
index 1c01f2cc7..1c01f2cc7 100644
--- a/doc/manual/src/expressions/language-constructs.md
+++ b/doc/manual/src/language/constructs.md
diff --git a/doc/manual/src/expressions/derivations.md b/doc/manual/src/language/derivations.md
index d26a33b7f..3391ec0d8 100644
--- a/doc/manual/src/expressions/derivations.md
+++ b/doc/manual/src/language/derivations.md
@@ -4,7 +4,7 @@ The most important built-in function is `derivation`, which is used to
 describe a single derivation (a build action). It takes as input a set,
 the attributes of which specify the inputs of the build.
 
-  - There must be an attribute named `system` whose value must be a
+  - There must be an attribute named [`system`]{#attr-system} whose value must be a
     string specifying a Nix system type, such as `"i686-linux"` or
     `"x86_64-darwin"`. (To figure out your system type, run `nix -vv
     --version`.) The build can only be performed on a machine and
diff --git a/doc/manual/src/language/index.md b/doc/manual/src/language/index.md
new file mode 100644
index 000000000..a4b402f8b
--- /dev/null
+++ b/doc/manual/src/language/index.md
@@ -0,0 +1,33 @@
+# Nix Language
+
+The Nix language is
+
+- *domain-specific*
+
+  It only exists for the Nix package manager:
+  to describe packages and configurations as well as their variants and compositions.
+  It is not intended for general purpose use.
+
+- *declarative*
+
+  There is no notion of executing sequential steps.
+  Dependencies between operations are established only through data.
+
+- *pure*
+
+  Values cannot change during computation.
+  Functions always produce the same output if their input does not change.
+
+- *functional*
+
+  Functions are like any other value.
+  Functions can be assigned to names, taken as arguments, or returned by functions.
+
+- *lazy*
+
+  Expressions are only evaluated when their value is needed.
+
+- *dynamically typed*
+
+  Type errors are only detected when expressions are evaluated.
+
diff --git a/doc/manual/src/expressions/language-operators.md b/doc/manual/src/language/operators.md
index 268b44f4c..32398189d 100644
--- a/doc/manual/src/expressions/language-operators.md
+++ b/doc/manual/src/language/operators.md
@@ -1,6 +1,6 @@
 # Operators
 
-The table below lists the operators in the Nix expression language, in
+The table below lists the operators in the Nix language, in
 order of precedence (from strongest to weakest binding).
 
 | Name                     | Syntax                              | Associativity | Description                                                                                                                                                                                                                   | Precedence |
diff --git a/doc/manual/src/language/values.md b/doc/manual/src/language/values.md
new file mode 100644
index 000000000..f09400d02
--- /dev/null
+++ b/doc/manual/src/language/values.md
@@ -0,0 +1,261 @@
+# Data Types
+
+## Primitives
+
+- <a id="type-string" href="#type-string">String</a>
+
+  *Strings* can be written in three ways.
+
+  The most common way is to enclose the string between double quotes,
+  e.g., `"foo bar"`. Strings can span multiple lines. The special
+  characters `"` and `\` and the character sequence `${` must be
+  escaped by prefixing them with a backslash (`\`). Newlines, carriage
+  returns and tabs can be written as `\n`, `\r` and `\t`,
+  respectively.
+
+  You can include the result of an expression into a string by
+  enclosing it in `${...}`, a feature known as *antiquotation*. The
+  enclosed expression must evaluate to something that can be coerced
+  into a string (meaning that it must be a string, a path, or a
+  derivation). For instance, rather than writing
+
+  ```nix
+  "--with-freetype2-library=" + freetype + "/lib"
+  ```
+
+  (where `freetype` is a derivation), you can instead write the more
+  natural
+
+  ```nix
+  "--with-freetype2-library=${freetype}/lib"
+  ```
+
+  The latter is automatically translated to the former. A more
+  complicated example (from the Nix expression for
+  [Qt](http://www.trolltech.com/products/qt)):
+
+  ```nix
+  configureFlags = "
+    -system-zlib -system-libpng -system-libjpeg
+    ${if openglSupport then "-dlopen-opengl
+      -L${mesa}/lib -I${mesa}/include
+      -L${libXmu}/lib -I${libXmu}/include" else ""}
+    ${if threadSupport then "-thread" else "-no-thread"}
+  ";
+  ```
+
+  Note that Nix expressions and strings can be arbitrarily nested; in
+  this case the outer string contains various antiquotations that
+  themselves contain strings (e.g., `"-thread"`), some of which in
+  turn contain expressions (e.g., `${mesa}`).
+
+  The second way to write string literals is as an *indented string*,
+  which is enclosed between pairs of *double single-quotes*, like so:
+
+  ```nix
+  ''
+    This is the first line.
+    This is the second line.
+      This is the third line.
+  ''
+  ```
+
+  This kind of string literal intelligently strips indentation from
+  the start of each line. To be precise, it strips from each line a
+  number of spaces equal to the minimal indentation of the string as a
+  whole (disregarding the indentation of empty lines). For instance,
+  the first and second line are indented two spaces, while the third
+  line is indented four spaces. Thus, two spaces are stripped from
+  each line, so the resulting string is
+
+  ```nix
+  "This is the first line.\nThis is the second line.\n  This is the third line.\n"
+  ```
+
+  Note that the whitespace and newline following the opening `''` is
+  ignored if there is no non-whitespace text on the initial line.
+
+  Antiquotation (`${expr}`) is supported in indented strings.
+
+  Since `${` and `''` have special meaning in indented strings, you
+  need a way to quote them. `$` can be escaped by prefixing it with
+  `''` (that is, two single quotes), i.e., `''$`. `''` can be escaped
+  by prefixing it with `'`, i.e., `'''`. `$` removes any special
+  meaning from the following `$`. Linefeed, carriage-return and tab
+  characters can be written as `''\n`, `''\r`, `''\t`, and `''\`
+  escapes any other character.
+
+  Indented strings are primarily useful in that they allow multi-line
+  string literals to follow the indentation of the enclosing Nix
+  expression, and that less escaping is typically necessary for
+  strings representing languages such as shell scripts and
+  configuration files because `''` is much less common than `"`.
+  Example:
+
+  ```nix
+  stdenv.mkDerivation {
+    ...
+    postInstall =
+      ''
+        mkdir $out/bin $out/etc
+        cp foo $out/bin
+        echo "Hello World" > $out/etc/foo.conf
+        ${if enableBar then "cp bar $out/bin" else ""}
+      '';
+    ...
+  }
+  ```
+
+  Finally, as a convenience, *URIs* as defined in appendix B of
+  [RFC 2396](http://www.ietf.org/rfc/rfc2396.txt) can be written *as
+  is*, without quotes. For instance, the string
+  `"http://example.org/foo.tar.bz2"` can also be written as
+  `http://example.org/foo.tar.bz2`.
+
+- <a id="type-number" href="#type-number">Number</a>
+
+  Numbers, which can be *integers* (like `123`) or *floating point*
+  (like `123.43` or `.27e13`).
+
+  Numbers are type-compatible: pure integer operations will always
+  return integers, whereas any operation involving at least one
+  floating point number will have a floating point number as a result.
+
+- <a id="type-path" href="#type-path">Path</a>
+
+  *Paths*, e.g., `/bin/sh` or `./builder.sh`. A path must contain at
+  least one slash to be recognised as such. For instance, `builder.sh`
+  is not a path: it's parsed as an expression that selects the
+  attribute `sh` from the variable `builder`. If the file name is
+  relative, i.e., if it does not begin with a slash, it is made
+  absolute at parse time relative to the directory of the Nix
+  expression that contained it. For instance, if a Nix expression in
+  `/foo/bar/bla.nix` refers to `../xyzzy/fnord.nix`, the absolute path
+  is `/foo/xyzzy/fnord.nix`.
+
+  If the first component of a path is a `~`, it is interpreted as if
+  the rest of the path were relative to the user's home directory.
+  e.g. `~/foo` would be equivalent to `/home/edolstra/foo` for a user
+  whose home directory is `/home/edolstra`.
+
+  Paths can also be specified between angle brackets, e.g.
+  `<nixpkgs>`. This means that the directories listed in the
+  environment variable `NIX_PATH` will be searched for the given file
+  or directory name.
+
+  Antiquotation is supported in any paths except those in angle brackets.
+  `./${foo}-${bar}.nix` is a more convenient way of writing
+  `./. + "/" + foo + "-" + bar + ".nix"` or `./. + "/${foo}-${bar}.nix"`. At
+  least one slash must appear *before* any antiquotations for this to be
+  recognized as a path. `a.${foo}/b.${bar}` is a syntactically valid division
+  operation. `./a.${foo}/b.${bar}` is a path.
+
+- <a id="type-boolean" href="#type-boolean">Boolean</a>
+
+  *Booleans* with values `true` and `false`.
+
+- <a id="type-null" href="#type-null">Null</a>
+
+  The null value, denoted as `null`.
+
+## List
+
+Lists are formed by enclosing a whitespace-separated list of values
+between square brackets. For example,
+
+```nix
+[ 123 ./foo.nix "abc" (f { x = y; }) ]
+```
+
+defines a list of four elements, the last being the result of a call to
+the function `f`. Note that function calls have to be enclosed in
+parentheses. If they had been omitted, e.g.,
+
+```nix
+[ 123 ./foo.nix "abc" f { x = y; } ]
+```
+
+the result would be a list of five elements, the fourth one being a
+function and the fifth being a set.
+
+Note that lists are only lazy in values, and they are strict in length.
+
+## Attribute Set
+
+An attribute set is a collection of name-value-pairs (called *attributes*) enclosed in curly brackets (`{ }`).
+
+Names and values are separated by an equal sign (`=`).
+Each value is an arbitrary expression terminated by a semicolon (`;`).
+
+Attributes can appear in any order.
+An attribute name may only occur once.
+
+Example:
+
+```nix
+{
+  x = 123;
+  text = "Hello";
+  y = f { bla = 456; };
+}
+```
+
+This defines a set with attributes named `x`, `text`, `y`.
+
+Attributes can be selected from a set using the `.` operator. For
+instance,
+
+```nix
+{ a = "Foo"; b = "Bar"; }.a
+```
+
+evaluates to `"Foo"`. It is possible to provide a default value in an
+attribute selection using the `or` keyword. For example,
+
+```nix
+{ a = "Foo"; b = "Bar"; }.c or "Xyzzy"
+```
+
+will evaluate to `"Xyzzy"` because there is no `c` attribute in the set.
+
+You can use arbitrary double-quoted strings as attribute names:
+
+```nix
+{ "foo ${bar}" = 123; "nix-1.0" = 456; }."foo ${bar}"
+```
+
+This will evaluate to `123` (Assuming `bar` is antiquotable). In the
+case where an attribute name is just a single antiquotation, the quotes
+can be dropped:
+
+```nix
+{ foo = 123; }.${bar} or 456
+```
+
+This will evaluate to `123` if `bar` evaluates to `"foo"` when coerced
+to a string and `456` otherwise (again assuming `bar` is antiquotable).
+
+In the special case where an attribute name inside of a set declaration
+evaluates to `null` (which is normally an error, as `null` is not
+antiquotable), that attribute is simply not added to the set:
+
+```nix
+{ ${if foo then "bar" else null} = true; }
+```
+
+This will evaluate to `{}` if `foo` evaluates to `false`.
+
+A set that has a `__functor` attribute whose value is callable (i.e. is
+itself a function or a set with a `__functor` attribute whose value is
+callable) can be applied as if it were a function, with the set itself
+passed in first , e.g.,
+
+```nix
+let add = { __functor = self: x: x + self.x; };
+    inc = add // { x = 1; };
+in inc 1
+```
+
+evaluates to `2`. This can be used to attach metadata to a function
+without the caller needing to treat it specially, or to implement a form
+of object-oriented programming, for example.
diff --git a/doc/manual/src/package-management/package-management.md b/doc/manual/src/package-management/package-management.md
index bd26a09ab..d528112e2 100644
--- a/doc/manual/src/package-management/package-management.md
+++ b/doc/manual/src/package-management/package-management.md
@@ -1,5 +1,4 @@
 This chapter discusses how to do package management with Nix, i.e.,
 how to obtain, install, upgrade, and erase packages. This is the
 “user’s” perspective of the Nix system — people who want to *create*
-packages should consult the [chapter on writing Nix
-expressions](../expressions/writing-nix-expressions.md).
+packages should consult the chapter on the [Nix language](../language/index.md).
diff --git a/doc/manual/src/release-notes/rl-2.10.md b/doc/manual/src/release-notes/rl-2.10.md
new file mode 100644
index 000000000..b99dbeef0
--- /dev/null
+++ b/doc/manual/src/release-notes/rl-2.10.md
@@ -0,0 +1,31 @@
+# Release 2.10 (2022-07-11)
+
+* `nix repl` now takes installables on the command line, unifying the usage
+  with other commands that use `--file` and `--expr`. Primary breaking change
+  is for the common usage of `nix repl '<nixpkgs>'` which can be recovered with
+  `nix repl --file '<nixpkgs>'` or `nix repl --expr 'import <nixpkgs>{}'`.
+
+  This is currently guarded by the `repl-flake` experimental feature.
+
+* A new function `builtins.traceVerbose` is available. It is similar
+  to `builtins.trace` if the `trace-verbose` setting is set to true,
+  and it is a no-op otherwise.
+
+* `nix search` has a new flag `--exclude` to filter out packages.
+
+* On Linux, if `/nix` doesn't exist and cannot be created and you're
+  not running as root, Nix will automatically use
+  `~/.local/share/nix/root` as a chroot store. This enables non-root
+  users to download the statically linked Nix binary and have it work
+  out of the box, e.g.
+
+  ```
+  # ~/nix run nixpkgs#hello
+  warning: '/nix' does not exists, so Nix will use '/home/ubuntu/.local/share/nix/root' as a chroot store
+  Hello, world!
+  ```
+
+* `flake-registry.json` is now fetched from `channels.nixos.org`.
+
+* Nix can now be built with LTO by passing `--enable-lto` to `configure`.
+  LTO is currently only supported when building with GCC.
diff --git a/doc/manual/src/release-notes/rl-2.11.md b/doc/manual/src/release-notes/rl-2.11.md
new file mode 100644
index 000000000..b322a4e5e
--- /dev/null
+++ b/doc/manual/src/release-notes/rl-2.11.md
@@ -0,0 +1,5 @@
+# Release 2.11 (2022-08-24)
+
+* `nix copy` now copies the store paths in parallel as much as possible (again).
+  This doesn't apply for the `daemon` and `ssh-ng` stores which copy everything
+  in one batch to avoid latencies issues.
diff --git a/doc/manual/src/release-notes/rl-2.9.md b/doc/manual/src/release-notes/rl-2.9.md
new file mode 100644
index 000000000..98cc4235d
--- /dev/null
+++ b/doc/manual/src/release-notes/rl-2.9.md
@@ -0,0 +1,47 @@
+# Release 2.9 (2022-05-30)
+
+* Running Nix with the new `--debugger` flag will cause it to start a
+  repl session if an exception is thrown during evaluation, or if
+  `builtins.break` is called.  From there you can inspect the values
+  of variables and evaluate Nix expressions.  In debug mode, the
+  following new repl commands are available:
+
+  ```
+  :env          Show env stack
+  :bt           Show trace stack
+  :st           Show current trace
+  :st <idx>     Change to another trace in the stack
+  :c            Go until end of program, exception, or builtins.break().
+  :s            Go one step
+  ```
+
+  Read more about the debugger
+  [here](https://www.zknotes.com/note/5970).
+
+* Nix now provides better integration with zsh's `run-help`
+  feature. It is now included in the Nix installation in the form of
+  an autoloadable shell function, `run-help-nix`. It picks up Nix
+  subcommands from the currently typed in command and directs the user
+  to the associated man pages.
+
+* `nix repl` has a new build-and-link (`:bl`) command that builds a
+  derivation while creating GC root symlinks.
+
+* The path produced by `builtins.toFile` is now allowed to be imported
+  or read even with restricted evaluation. Note that this will not
+  work with a read-only store.
+
+* `nix build` has a new `--print-out-paths` flag to print the
+  resulting output paths.  This matches the default behaviour of
+  `nix-build`.
+
+* You can now specify which outputs of a derivation `nix` should
+  operate on using the syntax `installable^outputs`,
+  e.g. `nixpkgs#glibc^dev,static` or `nixpkgs#glibc^*`. By default,
+  `nix` will use the outputs specified by the derivation's
+  `meta.outputsToInstall` attribute if it exists, or all outputs
+  otherwise.
+
+* `builtins.fetchTree` (and flake inputs) can now be used to fetch
+  plain files over the `http(s)` and `file` protocols in addition to
+  directory tarballs.
diff --git a/doc/manual/src/release-notes/rl-next.md b/doc/manual/src/release-notes/rl-next.md
index f312f2f86..f25fce758 100644
--- a/doc/manual/src/release-notes/rl-next.md
+++ b/doc/manual/src/release-notes/rl-next.md
@@ -1,20 +1,5 @@
 # Release X.Y (202?-??-??)
 
-* Nix now provides better integration with zsh's run-help feature. It is now
-  included in the Nix installation in the form of an autoloadable shell
-  function, run-help-nix. It picks up Nix subcommands from the currently typed
-  in command and directs the user to the associated man pages.
-
-* `nix repl` has a new build-'n-link (`:bl`) command that builds a derivation
-  while creating GC root symlinks.
-
-* The path produced by `builtins.toFile` is now allowed to be imported or read
-  even with restricted evaluation. Note that this will not work with a
-  read-only store.
-
-* `nix build` has a new `--print-out-paths` flag to print the resulting output paths.
-  This matches the default behaviour of `nix-build`.
-
 * Error traces have been reworked to provide detailed explanations and more
   accurate error locations. A short excerpt of the trace is now shown by
   default when an error occurs.