diff --git a/pkgs/applications/audio/lmms/default.nix b/pkgs/applications/audio/lmms/default.nix
index cba49b7afe50..5031a40afc7a 100644
--- a/pkgs/applications/audio/lmms/default.nix
+++ b/pkgs/applications/audio/lmms/default.nix
@@ -7,7 +7,7 @@
   alsa-lib ? null,
   carla ? null,
   fftwFloat,
-  fltk13,
+  fltk_1_3,
   fluidsynth ? null,
   lame ? null,
   libgig ? null,
@@ -47,7 +47,7 @@ mkDerivation rec {
     carla
     alsa-lib
     fftwFloat
-    fltk13
+    fltk_1_3
     fluidsynth
     lame
     libgig
diff --git a/pkgs/applications/editors/emacs/elisp-packages/elpa-common-overrides.nix b/pkgs/applications/editors/emacs/elisp-packages/elpa-common-overrides.nix
index 3074bd44c18e..1fc3f359f07e 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/elpa-common-overrides.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/elpa-common-overrides.nix
@@ -154,7 +154,7 @@ in
 
     nativeBuildInputs = old.nativeBuildInputs or [ ] ++ [ pkgs.pkg-config ];
 
-    buildInputs = old.buildInputs or [ ] ++ [ pkgs.enchant2 ];
+    buildInputs = old.buildInputs or [ ] ++ [ pkgs.enchant_2 ];
 
     postBuild =
       old.postBuild or ""
diff --git a/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix b/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
index cd304700ee5f..cd06872a5d1b 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/melpa-packages.nix
@@ -353,7 +353,7 @@ let
                 pkgs.pkg-config
               ];
 
-              buildInputs = (old.buildInputs or [ ]) ++ [ pkgs.enchant2 ];
+              buildInputs = (old.buildInputs or [ ]) ++ [ pkgs.enchant_2 ];
 
               postBuild = ''
                 NIX_CFLAGS_COMPILE="$($PKG_CONFIG --cflags enchant-2) $NIX_CFLAGS_COMPILE"
diff --git a/pkgs/applications/networking/remote/citrix-workspace/generic.nix b/pkgs/applications/networking/remote/citrix-workspace/generic.nix
index 2dc0171aa9c5..6a7afab23b3d 100644
--- a/pkgs/applications/networking/remote/citrix-workspace/generic.nix
+++ b/pkgs/applications/networking/remote/citrix-workspace/generic.nix
@@ -10,7 +10,7 @@
   cacert,
   cairo,
   dconf,
-  enchant2,
+  enchant,
   file,
   fontconfig,
   freetype,
@@ -153,7 +153,7 @@ stdenv.mkDerivation rec {
     atk
     cairo
     dconf
-    enchant2
+    enchant
     fontconfig
     freetype
     fuse3'
diff --git a/pkgs/applications/office/libreoffice/default.nix b/pkgs/applications/office/libreoffice/default.nix
index b6207c808046..a517dec53f94 100644
--- a/pkgs/applications/office/libreoffice/default.nix
+++ b/pkgs/applications/office/libreoffice/default.nix
@@ -66,7 +66,7 @@
   nspr,
   libwpg,
   dbus-glib,
-  clucene_core_2,
+  clucene-core_2,
   libcdr,
   lcms2,
   unixODBC,
@@ -408,7 +408,7 @@ stdenv.mkDerivation (finalAttrs: {
       bluez5
       box2d_2
       cairo
-      clucene_core_2
+      clucene-core_2
       cppunit
       cups
       curl
diff --git a/pkgs/applications/radio/fldigi/default.nix b/pkgs/applications/radio/fldigi/default.nix
index 695cfb9ef1a8..f15e934ded3c 100644
--- a/pkgs/applications/radio/fldigi/default.nix
+++ b/pkgs/applications/radio/fldigi/default.nix
@@ -3,7 +3,7 @@
   stdenv,
   fetchurl,
   hamlib,
-  fltk13,
+  fltk_1_3,
   libjpeg,
   libpng,
   portaudio,
@@ -32,7 +32,7 @@ stdenv.mkDerivation rec {
     libXinerama
     gettext
     hamlib
-    fltk13
+    fltk_1_3
     libjpeg
     libpng
     portaudio
diff --git a/pkgs/build-support/appimage/default.nix b/pkgs/build-support/appimage/default.nix
index 11de395dc1a0..fd95aea165d7 100644
--- a/pkgs/build-support/appimage/default.nix
+++ b/pkgs/build-support/appimage/default.nix
@@ -200,7 +200,7 @@ rec {
         libogg
         libvorbis
         SDL2_image
-        glew110
+        glew_1_10
         openssl
         libidn
         onetbb
diff --git a/pkgs/by-name/af/afterstep/package.nix b/pkgs/by-name/af/afterstep/package.nix
index f7b4e1634e4e..a71585cad7df 100644
--- a/pkgs/by-name/af/afterstep/package.nix
+++ b/pkgs/by-name/af/afterstep/package.nix
@@ -4,7 +4,7 @@
   fetchFromGitHub,
   fetchpatch,
   dbus,
-  fltk13,
+  fltk_1_3,
   gtk2,
   libICE,
   libSM,
@@ -58,7 +58,7 @@ stdenv.mkDerivation (finalAttrs: {
 
   buildInputs = [
     dbus
-    fltk13
+    fltk_1_3
     gtk2
     libICE
     libSM
diff --git a/pkgs/development/libraries/agg/default.nix b/pkgs/by-name/ag/agg/package.nix
similarity index 98%
rename from pkgs/development/libraries/agg/default.nix
rename to pkgs/by-name/ag/agg/package.nix
index 6ba398223771..b55eb554d94e 100644
--- a/pkgs/development/libraries/agg/default.nix
+++ b/pkgs/by-name/ag/agg/package.nix
@@ -1,6 +1,6 @@
 {
   lib,
-  stdenv,
+  gccStdenv,
   fetchurl,
   autoconf,
   automake,
@@ -10,7 +10,9 @@
   SDL,
   libX11,
 }:
-
+let
+  stdenv = gccStdenv;
+in
 stdenv.mkDerivation rec {
   pname = "agg";
   version = "2.5";
diff --git a/pkgs/by-name/al/alsa-tools/package.nix b/pkgs/by-name/al/alsa-tools/package.nix
index 82f238d16190..140f8bd4f2ad 100644
--- a/pkgs/by-name/al/alsa-tools/package.nix
+++ b/pkgs/by-name/al/alsa-tools/package.nix
@@ -3,7 +3,7 @@
   stdenv,
   fetchurl,
   alsa-lib,
-  fltk13,
+  fltk_1_3,
   gtk2,
   gtk3,
   makeWrapper,
@@ -27,7 +27,7 @@ stdenv.mkDerivation (finalAttrs: {
 
   buildInputs = [
     alsa-lib
-    fltk13
+    fltk_1_3
     gtk2
     gtk3
     psmisc
diff --git a/pkgs/development/libraries/atkmm/default.nix b/pkgs/by-name/at/atkmm/package.nix
similarity index 100%
rename from pkgs/development/libraries/atkmm/default.nix
rename to pkgs/by-name/at/atkmm/package.nix
diff --git a/pkgs/development/libraries/atkmm/2.36.nix b/pkgs/by-name/at/atkmm_2_36/package.nix
similarity index 100%
rename from pkgs/development/libraries/atkmm/2.36.nix
rename to pkgs/by-name/at/atkmm_2_36/package.nix
diff --git a/pkgs/development/libraries/avahi/default.nix b/pkgs/by-name/av/avahi/package.nix
similarity index 100%
rename from pkgs/development/libraries/avahi/default.nix
rename to pkgs/by-name/av/avahi/package.nix
diff --git a/pkgs/by-name/bi/bibletime/package.nix b/pkgs/by-name/bi/bibletime/package.nix
index bc9fb7836e05..61e7063f4324 100644
--- a/pkgs/by-name/bi/bibletime/package.nix
+++ b/pkgs/by-name/bi/bibletime/package.nix
@@ -1,7 +1,7 @@
 {
   lib,
   boost,
-  clucene_core_2,
+  clucene-core_2,
   cmake,
   docbook_xml_dtd_45,
   docbook_xsl_ns,
@@ -46,7 +46,7 @@ stdenv.mkDerivation (finalAttrs: {
 
   buildInputs = [
     boost
-    clucene_core_2
+    clucene-core_2
     qtbase
     qtsvg
     qttools
@@ -54,7 +54,7 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   preConfigure = ''
-    export CLUCENE_HOME=${clucene_core_2};
+    export CLUCENE_HOME=${clucene-core_2};
     export SWORD_HOME=${sword};
   '';
 
diff --git a/pkgs/by-name/bl/blackvoxel/package.nix b/pkgs/by-name/bl/blackvoxel/package.nix
index 7b2b938a5c61..38faa31818c6 100644
--- a/pkgs/by-name/bl/blackvoxel/package.nix
+++ b/pkgs/by-name/bl/blackvoxel/package.nix
@@ -4,7 +4,7 @@
   fetchFromGitHub,
   makeDesktopItem,
   imagemagick,
-  glew110,
+  glew_1_10,
   SDL_compat,
   nix-update-script,
 }:
@@ -23,7 +23,7 @@ stdenv.mkDerivation (finalAttrs: {
   nativeBuildInputs = [ imagemagick ];
 
   buildInputs = [
-    glew110
+    glew_1_10
     SDL_compat
   ];
 
diff --git a/pkgs/by-name/bu/butt/package.nix b/pkgs/by-name/bu/butt/package.nix
index 53dc3e89440e..3050588c06b8 100644
--- a/pkgs/by-name/bu/butt/package.nix
+++ b/pkgs/by-name/bu/butt/package.nix
@@ -3,7 +3,7 @@
   stdenv,
   fetchurl,
   pkg-config,
-  fltk13,
+  fltk_1_3,
   portaudio,
   lame,
   libvorbis,
@@ -43,7 +43,7 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   buildInputs = [
-    fltk13
+    fltk_1_3
     portaudio
     lame
     libvorbis
diff --git a/pkgs/development/libraries/c-ares/fix-link-local-dns-servers.patch b/pkgs/by-name/c-/c-ares/fix-link-local-dns-servers.patch
similarity index 100%
rename from pkgs/development/libraries/c-ares/fix-link-local-dns-servers.patch
rename to pkgs/by-name/c-/c-ares/fix-link-local-dns-servers.patch
diff --git a/pkgs/development/libraries/c-ares/default.nix b/pkgs/by-name/c-/c-ares/package.nix
similarity index 100%
rename from pkgs/development/libraries/c-ares/default.nix
rename to pkgs/by-name/c-/c-ares/package.nix
diff --git a/pkgs/development/libraries/c-blosc/1.nix b/pkgs/by-name/c-/c-blosc/package.nix
similarity index 100%
rename from pkgs/development/libraries/c-blosc/1.nix
rename to pkgs/by-name/c-/c-blosc/package.nix
diff --git a/pkgs/development/libraries/c-blosc/2.nix b/pkgs/by-name/c-/c-blosc2/package.nix
similarity index 100%
rename from pkgs/development/libraries/c-blosc/2.nix
rename to pkgs/by-name/c-/c-blosc2/package.nix
diff --git a/pkgs/development/libraries/cairomm/default.nix b/pkgs/by-name/ca/cairomm/package.nix
similarity index 100%
rename from pkgs/development/libraries/cairomm/default.nix
rename to pkgs/by-name/ca/cairomm/package.nix
diff --git a/pkgs/development/libraries/cairomm/1.16.nix b/pkgs/by-name/ca/cairomm_1_16/package.nix
similarity index 100%
rename from pkgs/development/libraries/cairomm/1.16.nix
rename to pkgs/by-name/ca/cairomm_1_16/package.nix
diff --git a/pkgs/development/libraries/capstone/default.nix b/pkgs/by-name/ca/capstone/package.nix
similarity index 100%
rename from pkgs/development/libraries/capstone/default.nix
rename to pkgs/by-name/ca/capstone/package.nix
diff --git a/pkgs/development/libraries/capstone/4.nix b/pkgs/by-name/ca/capstone_4/package.nix
similarity index 100%
rename from pkgs/development/libraries/capstone/4.nix
rename to pkgs/by-name/ca/capstone_4/package.nix
diff --git a/pkgs/development/libraries/cassandra-cpp-driver/default.nix b/pkgs/by-name/ca/cassandra-cpp-driver/package.nix
similarity index 100%
rename from pkgs/development/libraries/cassandra-cpp-driver/default.nix
rename to pkgs/by-name/ca/cassandra-cpp-driver/package.nix
diff --git a/pkgs/development/libraries/cctag/cmake-install-include-dir.patch b/pkgs/by-name/cc/cctag/cmake-install-include-dir.patch
similarity index 100%
rename from pkgs/development/libraries/cctag/cmake-install-include-dir.patch
rename to pkgs/by-name/cc/cctag/cmake-install-include-dir.patch
diff --git a/pkgs/development/libraries/cctag/cmake-no-apple-rpath.patch b/pkgs/by-name/cc/cctag/cmake-no-apple-rpath.patch
similarity index 100%
rename from pkgs/development/libraries/cctag/cmake-no-apple-rpath.patch
rename to pkgs/by-name/cc/cctag/cmake-no-apple-rpath.patch
diff --git a/pkgs/development/libraries/cctag/default.nix b/pkgs/by-name/cc/cctag/package.nix
similarity index 93%
rename from pkgs/development/libraries/cctag/default.nix
rename to pkgs/by-name/cc/cctag/package.nix
index 60de365c149e..37cb19617b65 100644
--- a/pkgs/development/libraries/cctag/default.nix
+++ b/pkgs/by-name/cc/cctag/package.nix
@@ -1,6 +1,6 @@
 {
   lib,
-  stdenv,
+  clangStdenv,
   fetchFromGitHub,
 
   cmake,
@@ -9,9 +9,11 @@
   opencv,
   onetbb,
 
-  avx2Support ? stdenv.hostPlatform.avx2Support,
+  avx2Support ? clangStdenv.hostPlatform.avx2Support,
 }:
-
+let
+  stdenv = clangStdenv;
+in
 stdenv.mkDerivation rec {
   pname = "cctag";
   version = "1.0.4";
diff --git a/pkgs/development/libraries/ceres-solver/default.nix b/pkgs/by-name/ce/ceres-solver/package.nix
similarity index 100%
rename from pkgs/development/libraries/ceres-solver/default.nix
rename to pkgs/by-name/ce/ceres-solver/package.nix
diff --git a/pkgs/development/libraries/clucene-core/Fix-pkgconfig-file-by-adding-clucene-shared-library.patch b/pkgs/by-name/cl/clucene-core_2/Fix-pkgconfig-file-by-adding-clucene-shared-library.patch
similarity index 100%
rename from pkgs/development/libraries/clucene-core/Fix-pkgconfig-file-by-adding-clucene-shared-library.patch
rename to pkgs/by-name/cl/clucene-core_2/Fix-pkgconfig-file-by-adding-clucene-shared-library.patch
diff --git a/pkgs/development/libraries/clucene-core/Fixing_ZLIB_configuration_in_shared_CMakeLists.patch b/pkgs/by-name/cl/clucene-core_2/Fixing_ZLIB_configuration_in_shared_CMakeLists.patch
similarity index 100%
rename from pkgs/development/libraries/clucene-core/Fixing_ZLIB_configuration_in_shared_CMakeLists.patch
rename to pkgs/by-name/cl/clucene-core_2/Fixing_ZLIB_configuration_in_shared_CMakeLists.patch
diff --git a/pkgs/development/libraries/clucene-core/Install-contribs-lib.patch b/pkgs/by-name/cl/clucene-core_2/Install-contribs-lib.patch
similarity index 100%
rename from pkgs/development/libraries/clucene-core/Install-contribs-lib.patch
rename to pkgs/by-name/cl/clucene-core_2/Install-contribs-lib.patch
diff --git a/pkgs/development/libraries/clucene-core/fix-darwin.patch b/pkgs/by-name/cl/clucene-core_2/fix-darwin.patch
similarity index 100%
rename from pkgs/development/libraries/clucene-core/fix-darwin.patch
rename to pkgs/by-name/cl/clucene-core_2/fix-darwin.patch
diff --git a/pkgs/development/libraries/clucene-core/fix-missing-include-time.patch b/pkgs/by-name/cl/clucene-core_2/fix-missing-include-time.patch
similarity index 100%
rename from pkgs/development/libraries/clucene-core/fix-missing-include-time.patch
rename to pkgs/by-name/cl/clucene-core_2/fix-missing-include-time.patch
diff --git a/pkgs/development/libraries/clucene-core/2.x.nix b/pkgs/by-name/cl/clucene-core_2/package.nix
similarity index 100%
rename from pkgs/development/libraries/clucene-core/2.x.nix
rename to pkgs/by-name/cl/clucene-core_2/package.nix
diff --git a/pkgs/development/libraries/clucene-core/pthread-include.patch b/pkgs/by-name/cl/clucene-core_2/pthread-include.patch
similarity index 100%
rename from pkgs/development/libraries/clucene-core/pthread-include.patch
rename to pkgs/by-name/cl/clucene-core_2/pthread-include.patch
diff --git a/pkgs/development/libraries/dbus/implement-getgrouplist.patch b/pkgs/by-name/db/dbus/implement-getgrouplist.patch
similarity index 100%
rename from pkgs/development/libraries/dbus/implement-getgrouplist.patch
rename to pkgs/by-name/db/dbus/implement-getgrouplist.patch
diff --git a/pkgs/development/libraries/dbus/default.nix b/pkgs/by-name/db/dbus/package.nix
similarity index 100%
rename from pkgs/development/libraries/dbus/default.nix
rename to pkgs/by-name/db/dbus/package.nix
diff --git a/pkgs/by-name/do/dovecot/package.nix b/pkgs/by-name/do/dovecot/package.nix
index 92757140467b..52cd9b4b1e05 100644
--- a/pkgs/by-name/do/dovecot/package.nix
+++ b/pkgs/by-name/do/dovecot/package.nix
@@ -17,7 +17,7 @@
   pam,
   libcap,
   coreutils,
-  clucene_core_2,
+  clucene-core_2,
   icu75,
   libexttextcat,
   libsodium,
@@ -63,7 +63,7 @@ stdenv.mkDerivation rec {
     zlib
     zstd
     xz
-    clucene_core_2
+    clucene-core_2
     icu75
     libexttextcat
     libsodium
diff --git a/pkgs/development/libraries/draco/default.nix b/pkgs/by-name/dr/draco/package.nix
similarity index 96%
rename from pkgs/development/libraries/draco/default.nix
rename to pkgs/by-name/dr/draco/package.nix
index d165b96ea1e3..24352556e86a 100644
--- a/pkgs/development/libraries/draco/default.nix
+++ b/pkgs/by-name/dr/draco/package.nix
@@ -1,5 +1,6 @@
 {
   lib,
+  callPackage,
   stdenv,
   fetchFromGitHub,
   nix-update-script,
@@ -10,11 +11,11 @@
   withTranscoder ? true,
   eigen,
   ghc_filesystem,
-  tinygltf,
 }:
 
 let
   cmakeBool = b: if b then "ON" else "OFF";
+  tinygltf = callPackage ./tinygltf.nix { };
 in
 stdenv.mkDerivation (finalAttrs: {
   version = "1.5.7";
diff --git a/pkgs/development/libraries/draco/tinygltf.nix b/pkgs/by-name/dr/draco/tinygltf.nix
similarity index 100%
rename from pkgs/development/libraries/draco/tinygltf.nix
rename to pkgs/by-name/dr/draco/tinygltf.nix
diff --git a/pkgs/development/libraries/eccodes/default.nix b/pkgs/by-name/ec/eccodes/package.nix
similarity index 94%
rename from pkgs/development/libraries/eccodes/default.nix
rename to pkgs/by-name/ec/eccodes/package.nix
index 84ee929e0d1c..5ea1a9d7df36 100644
--- a/pkgs/development/libraries/eccodes/default.nix
+++ b/pkgs/by-name/ec/eccodes/package.nix
@@ -1,7 +1,7 @@
 {
-  fetchurl,
   lib,
-  stdenv,
+  gccStdenv,
+  fetchurl,
   cmake,
   netcdf,
   openjpeg,
@@ -11,12 +11,11 @@
   perl,
   ctestCheckHook,
   enablePython ? false,
-  pythonPackages,
+  python3Packages ? null,
   enablePosixThreads ? false,
   enableOpenMPThreads ? false,
 }:
-
-stdenv.mkDerivation rec {
+gccStdenv.mkDerivation rec {
   pname = "eccodes";
   version = "2.44.0";
 
@@ -54,8 +53,8 @@ stdenv.mkDerivation rec {
   ];
 
   propagatedBuildInputs = lib.optionals enablePython [
-    pythonPackages.python
-    pythonPackages.numpy
+    python3Packages.python
+    python3Packages.numpy
   ];
 
   cmakeFlags = [
diff --git a/pkgs/development/libraries/enchant/2.x.nix b/pkgs/by-name/en/enchant_2/package.nix
similarity index 100%
rename from pkgs/development/libraries/enchant/2.x.nix
rename to pkgs/by-name/en/enchant_2/package.nix
diff --git a/pkgs/development/libraries/farstream/default.nix b/pkgs/by-name/fa/farstream/package.nix
similarity index 88%
rename from pkgs/development/libraries/farstream/default.nix
rename to pkgs/by-name/fa/farstream/package.nix
index d1432913b256..43549ba0b0c9 100644
--- a/pkgs/development/libraries/farstream/default.nix
+++ b/pkgs/by-name/fa/farstream/package.nix
@@ -3,16 +3,12 @@
   stdenv,
   fetchurl,
   fetchpatch,
+  buildPackages,
   libnice,
   pkg-config,
-  autoreconfHook,
-  gstreamer,
-  gst-plugins-base,
+  gst_all_1,
   gupnp-igd,
   gobject-introspection,
-  gst-plugins-good,
-  gst-plugins-bad,
-  gst-libav,
   python3,
 }:
 
@@ -46,12 +42,12 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [
     pkg-config
-    autoreconfHook
+    buildPackages.autoreconfHook269
     gobject-introspection
     python3
   ];
 
-  propagatedBuildInputs = [
+  propagatedBuildInputs = with gst_all_1; [
     gstreamer
     gst-plugins-base
     gst-plugins-good
diff --git a/pkgs/by-name/fl/flamp/package.nix b/pkgs/by-name/fl/flamp/package.nix
index 79f5e2999ea5..841a43c6a9f5 100644
--- a/pkgs/by-name/fl/flamp/package.nix
+++ b/pkgs/by-name/fl/flamp/package.nix
@@ -4,7 +4,7 @@
   fetchgit,
   autoreconfHook,
   pkg-config,
-  fltk13,
+  fltk_1_3,
   gettext,
 }:
 
@@ -25,7 +25,7 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   buildInputs = [
-    fltk13
+    fltk_1_3
   ];
 
   enableParallelBuilding = true;
diff --git a/pkgs/development/libraries/flatbuffers/default.nix b/pkgs/by-name/fl/flatbuffers/package.nix
similarity index 100%
rename from pkgs/development/libraries/flatbuffers/default.nix
rename to pkgs/by-name/fl/flatbuffers/package.nix
diff --git a/pkgs/development/libraries/flatbuffers/23.nix b/pkgs/by-name/fl/flatbuffers_23/package.nix
similarity index 100%
rename from pkgs/development/libraries/flatbuffers/23.nix
rename to pkgs/by-name/fl/flatbuffers_23/package.nix
diff --git a/pkgs/by-name/fl/flightgear/package.nix b/pkgs/by-name/fl/flightgear/package.nix
index d2d05b651f0d..929d8019f937 100644
--- a/pkgs/by-name/fl/flightgear/package.nix
+++ b/pkgs/by-name/fl/flightgear/package.nix
@@ -25,7 +25,7 @@
   cmake,
   libpng,
   udev,
-  fltk13,
+  fltk_1_3,
   apr,
   qt5,
   glew,
@@ -93,7 +93,7 @@ stdenv.mkDerivation rec {
     boost
     libpng
     udev
-    fltk13
+    fltk_1_3
     apr
     qt5.qtbase
     qt5.qtquickcontrols2
diff --git a/pkgs/by-name/fl/fllog/package.nix b/pkgs/by-name/fl/fllog/package.nix
index 80e8f96ed4e6..3a49e0f43048 100644
--- a/pkgs/by-name/fl/fllog/package.nix
+++ b/pkgs/by-name/fl/fllog/package.nix
@@ -2,7 +2,7 @@
   lib,
   stdenv,
   fetchurl,
-  fltk13,
+  fltk_1_3,
   libjpeg,
   pkg-config,
 }:
@@ -17,12 +17,12 @@ stdenv.mkDerivation rec {
   };
 
   buildInputs = [
-    fltk13
+    fltk_1_3
     libjpeg
   ];
 
   nativeBuildInputs = [
-    fltk13 # fltk-config
+    fltk_1_3 # fltk-config
     pkg-config
   ];
 
diff --git a/pkgs/by-name/fl/flmsg/package.nix b/pkgs/by-name/fl/flmsg/package.nix
index 4dd5825472ce..4ad285524d3a 100644
--- a/pkgs/by-name/fl/flmsg/package.nix
+++ b/pkgs/by-name/fl/flmsg/package.nix
@@ -2,7 +2,7 @@
   lib,
   stdenv,
   fetchurl,
-  fltk13,
+  fltk_1_3,
   libjpeg,
   pkg-config,
 }:
@@ -17,7 +17,7 @@ stdenv.mkDerivation rec {
   };
 
   buildInputs = [
-    fltk13
+    fltk_1_3
     libjpeg
   ];
 
diff --git a/pkgs/by-name/fl/flpsed/package.nix b/pkgs/by-name/fl/flpsed/package.nix
index 4171a77d0901..a8662e465487 100644
--- a/pkgs/by-name/fl/flpsed/package.nix
+++ b/pkgs/by-name/fl/flpsed/package.nix
@@ -2,7 +2,7 @@
   lib,
   stdenv,
   fetchurl,
-  fltk13,
+  fltk_1_3,
   ghostscript,
 }:
 
@@ -15,7 +15,7 @@ stdenv.mkDerivation rec {
     sha256 = "0vngqxanykicabhfdznisv82k5ypkxwg0s93ms9ribvhpm8vf2xp";
   };
 
-  buildInputs = [ fltk13 ];
+  buildInputs = [ fltk_1_3 ];
 
   postPatch = ''
     # replace the execvp call to ghostscript
@@ -26,7 +26,7 @@ stdenv.mkDerivation rec {
   configureFlags = [
     "ac_cv_func_malloc_0_nonnull=yes"
     "ac_cv_func_realloc_0_nonnull=yes"
-    "FLTKCONFIG=${lib.getExe' (lib.getDev fltk13) "fltk-config"}"
+    "FLTKCONFIG=${lib.getExe' (lib.getDev fltk_1_3) "fltk-config"}"
   ];
 
   meta = {
diff --git a/pkgs/by-name/fl/flrig/package.nix b/pkgs/by-name/fl/flrig/package.nix
index de57d3647394..b0390c36501f 100644
--- a/pkgs/by-name/fl/flrig/package.nix
+++ b/pkgs/by-name/fl/flrig/package.nix
@@ -2,7 +2,7 @@
   lib,
   stdenv,
   fetchurl,
-  fltk13,
+  fltk_1_3,
   libjpeg,
   eudev,
   pkg-config,
@@ -18,7 +18,7 @@ stdenv.mkDerivation rec {
   };
 
   buildInputs = [
-    fltk13
+    fltk_1_3
     libjpeg
     eudev
   ];
@@ -27,7 +27,7 @@ stdenv.mkDerivation rec {
     pkg-config
   ];
 
-  env.FLTK_CONFIG = lib.getExe' (lib.getDev fltk13) "fltk-config";
+  env.FLTK_CONFIG = lib.getExe' (lib.getDev fltk_1_3) "fltk-config";
 
   meta = {
     description = "Digital modem rig control program";
diff --git a/pkgs/development/libraries/fltk/nsosv.patch b/pkgs/by-name/fl/fltk_1_3/nsosv.patch
similarity index 100%
rename from pkgs/development/libraries/fltk/nsosv.patch
rename to pkgs/by-name/fl/fltk_1_3/nsosv.patch
diff --git a/pkgs/development/libraries/fltk/default.nix b/pkgs/by-name/fl/fltk_1_3/package.nix
similarity index 100%
rename from pkgs/development/libraries/fltk/default.nix
rename to pkgs/by-name/fl/fltk_1_3/package.nix
diff --git a/pkgs/development/libraries/fltk/1.4.nix b/pkgs/by-name/fl/fltk_1_4/package.nix
similarity index 100%
rename from pkgs/development/libraries/fltk/1.4.nix
rename to pkgs/by-name/fl/fltk_1_4/package.nix
diff --git a/pkgs/by-name/fl/flwrap/package.nix b/pkgs/by-name/fl/flwrap/package.nix
index 1666191e48a5..5ec29e1d11c8 100644
--- a/pkgs/by-name/fl/flwrap/package.nix
+++ b/pkgs/by-name/fl/flwrap/package.nix
@@ -2,7 +2,7 @@
   lib,
   stdenv,
   fetchurl,
-  fltk13,
+  fltk_1_3,
   libjpeg,
   pkg-config,
 }:
@@ -21,12 +21,12 @@ stdenv.mkDerivation rec {
   ];
 
   buildInputs = [
-    fltk13
+    fltk_1_3
     libjpeg
   ];
 
   configureFlags = [
-    "FLTK_CONFIG=${lib.getExe' (lib.getDev fltk13) "fltk-config"}"
+    "FLTK_CONFIG=${lib.getExe' (lib.getDev fltk_1_3) "fltk-config"}"
   ];
 
   meta = {
diff --git a/pkgs/development/libraries/fox/default.nix b/pkgs/by-name/fo/fox/package.nix
similarity index 100%
rename from pkgs/development/libraries/fox/default.nix
rename to pkgs/by-name/fo/fox/package.nix
diff --git a/pkgs/development/libraries/fox/fox-1.6.nix b/pkgs/by-name/fo/fox_1_6/package.nix
similarity index 100%
rename from pkgs/development/libraries/fox/fox-1.6.nix
rename to pkgs/by-name/fo/fox_1_6/package.nix
diff --git a/pkgs/development/libraries/fplll/default.nix b/pkgs/by-name/fp/fplll/package.nix
similarity index 100%
rename from pkgs/development/libraries/fplll/default.nix
rename to pkgs/by-name/fp/fplll/package.nix
diff --git a/pkgs/development/libraries/fplll/20160331.nix b/pkgs/by-name/fp/fplll_20160331/package.nix
similarity index 100%
rename from pkgs/development/libraries/fplll/20160331.nix
rename to pkgs/by-name/fp/fplll_20160331/package.nix
diff --git a/pkgs/development/libraries/gamenetworkingsockets/default.nix b/pkgs/by-name/ga/gamenetworkingsockets/package.nix
similarity index 94%
rename from pkgs/development/libraries/gamenetworkingsockets/default.nix
rename to pkgs/by-name/ga/gamenetworkingsockets/package.nix
index 2cfeeacb61a2..21a4924ff3d8 100644
--- a/pkgs/development/libraries/gamenetworkingsockets/default.nix
+++ b/pkgs/by-name/ga/gamenetworkingsockets/package.nix
@@ -5,10 +5,12 @@
   cmake,
   ninja,
   go,
-  protobuf,
+  protobuf_21,
   openssl,
 }:
-
+let
+  protobuf = protobuf_21;
+in
 stdenv.mkDerivation rec {
   pname = "GameNetworkingSockets";
   version = "1.4.1";
diff --git a/pkgs/development/libraries/gcr/default.nix b/pkgs/by-name/gc/gcr/package.nix
similarity index 100%
rename from pkgs/development/libraries/gcr/default.nix
rename to pkgs/by-name/gc/gcr/package.nix
diff --git a/pkgs/development/libraries/gcr/4.nix b/pkgs/by-name/gc/gcr_4/package.nix
similarity index 100%
rename from pkgs/development/libraries/gcr/4.nix
rename to pkgs/by-name/gc/gcr_4/package.nix
diff --git a/pkgs/development/libraries/gdcm/add-missing-losslylosslessarray-in-TestTransferSyntax.patch b/pkgs/by-name/gd/gdcm/add-missing-losslylosslessarray-in-TestTransferSyntax.patch
similarity index 100%
rename from pkgs/development/libraries/gdcm/add-missing-losslylosslessarray-in-TestTransferSyntax.patch
rename to pkgs/by-name/gd/gdcm/add-missing-losslylosslessarray-in-TestTransferSyntax.patch
diff --git a/pkgs/development/libraries/gdcm/fix-vtk-deprecated-api.patch b/pkgs/by-name/gd/gdcm/fix-vtk-deprecated-api.patch
similarity index 100%
rename from pkgs/development/libraries/gdcm/fix-vtk-deprecated-api.patch
rename to pkgs/by-name/gd/gdcm/fix-vtk-deprecated-api.patch
diff --git a/pkgs/development/libraries/gdcm/default.nix b/pkgs/by-name/gd/gdcm/package.nix
similarity index 97%
rename from pkgs/development/libraries/gdcm/default.nix
rename to pkgs/by-name/gd/gdcm/package.nix
index ecd613650b38..e2241dfa9340 100644
--- a/pkgs/development/libraries/gdcm/default.nix
+++ b/pkgs/by-name/gd/gdcm/package.nix
@@ -6,7 +6,7 @@
   cmake,
   enableVTK ? true,
   vtk,
-  DarwinTools, # sw_vers
+  darwin, # sw_vers
   enablePython ? false,
   python ? null,
   swig,
@@ -61,7 +61,7 @@ stdenv.mkDerivation (finalAttrs: {
     cmake
     pkg-config
   ]
-  ++ lib.optional stdenv.hostPlatform.isDarwin DarwinTools;
+  ++ lib.optional stdenv.hostPlatform.isDarwin darwin.DarwinTools;
 
   buildInputs = [
     expat
diff --git a/pkgs/development/libraries/gdcm/python_gdcm.egg-info b/pkgs/by-name/gd/gdcm/python_gdcm.egg-info
similarity index 100%
rename from pkgs/development/libraries/gdcm/python_gdcm.egg-info
rename to pkgs/by-name/gd/gdcm/python_gdcm.egg-info
diff --git a/pkgs/development/libraries/gdk-pixbuf/xlib.nix b/pkgs/by-name/gd/gdk-pixbuf-xlib/package.nix
similarity index 100%
rename from pkgs/development/libraries/gdk-pixbuf/xlib.nix
rename to pkgs/by-name/gd/gdk-pixbuf-xlib/package.nix
diff --git a/pkgs/development/libraries/gdk-pixbuf/installed-tests-path.patch b/pkgs/by-name/gd/gdk-pixbuf/installed-tests-path.patch
similarity index 100%
rename from pkgs/development/libraries/gdk-pixbuf/installed-tests-path.patch
rename to pkgs/by-name/gd/gdk-pixbuf/installed-tests-path.patch
diff --git a/pkgs/development/libraries/gdk-pixbuf/default.nix b/pkgs/by-name/gd/gdk-pixbuf/package.nix
similarity index 100%
rename from pkgs/development/libraries/gdk-pixbuf/default.nix
rename to pkgs/by-name/gd/gdk-pixbuf/package.nix
diff --git a/pkgs/development/libraries/gdk-pixbuf/setup-hook.sh b/pkgs/by-name/gd/gdk-pixbuf/setup-hook.sh
similarity index 100%
rename from pkgs/development/libraries/gdk-pixbuf/setup-hook.sh
rename to pkgs/by-name/gd/gdk-pixbuf/setup-hook.sh
diff --git a/pkgs/by-name/ge/geary/package.nix b/pkgs/by-name/ge/geary/package.nix
index 9602715f550f..b741ac74f993 100644
--- a/pkgs/by-name/ge/geary/package.nix
+++ b/pkgs/by-name/ge/geary/package.nix
@@ -5,7 +5,7 @@
   pkg-config,
   gtk3,
   vala,
-  enchant2,
+  enchant,
   wrapGAppsHook3,
   meson,
   ninja,
@@ -70,7 +70,7 @@ stdenv.mkDerivation rec {
 
   buildInputs = [
     adwaita-icon-theme
-    enchant2
+    enchant
     folks
     gcr
     glib-networking
diff --git a/pkgs/development/libraries/gegl/default.nix b/pkgs/by-name/ge/gegl/package.nix
similarity index 98%
rename from pkgs/development/libraries/gegl/default.nix
rename to pkgs/by-name/ge/gegl/package.nix
index 00ccd6ae9170..9ae0814d0610 100644
--- a/pkgs/development/libraries/gegl/default.nix
+++ b/pkgs/by-name/ge/gegl/package.nix
@@ -29,7 +29,7 @@
   gexiv2,
   libwebp,
   luajit,
-  openexr,
+  openexr_2,
   suitesparse,
   withLuaJIT ? lib.meta.availableOn stdenv.hostPlatform luajit,
   gimp,
@@ -77,7 +77,7 @@ stdenv.mkDerivation (finalAttrs: {
     libraw
     libwebp
     gexiv2
-    openexr
+    openexr_2
     suitesparse
   ]
   ++ lib.optionals stdenv.cc.isClang [
diff --git a/pkgs/development/libraries/geoip/default.nix b/pkgs/by-name/ge/geoip/package.nix
similarity index 100%
rename from pkgs/development/libraries/geoip/default.nix
rename to pkgs/by-name/ge/geoip/package.nix
diff --git a/pkgs/development/libraries/glew/default.nix b/pkgs/by-name/gl/glew/package.nix
similarity index 100%
rename from pkgs/development/libraries/glew/default.nix
rename to pkgs/by-name/gl/glew/package.nix
diff --git a/pkgs/development/libraries/glew/1.10.nix b/pkgs/by-name/gl/glew_1_10/package.nix
similarity index 100%
rename from pkgs/development/libraries/glew/1.10.nix
rename to pkgs/by-name/gl/glew_1_10/package.nix
diff --git a/pkgs/development/libraries/glfw/2.x.nix b/pkgs/by-name/gl/glfw2/package.nix
similarity index 100%
rename from pkgs/development/libraries/glfw/2.x.nix
rename to pkgs/by-name/gl/glfw2/package.nix
diff --git a/pkgs/development/libraries/glibmm/default.nix b/pkgs/by-name/gl/glibmm/package.nix
similarity index 100%
rename from pkgs/development/libraries/glibmm/default.nix
rename to pkgs/by-name/gl/glibmm/package.nix
diff --git a/pkgs/development/libraries/glibmm/2.68.nix b/pkgs/by-name/gl/glibmm_2_68/package.nix
similarity index 100%
rename from pkgs/development/libraries/glibmm/2.68.nix
rename to pkgs/by-name/gl/glibmm_2_68/package.nix
diff --git a/pkgs/development/libraries/gnutls/dummy.crt b/pkgs/by-name/gn/gnutls/dummy.crt
similarity index 100%
rename from pkgs/development/libraries/gnutls/dummy.crt
rename to pkgs/by-name/gn/gnutls/dummy.crt
diff --git a/pkgs/development/libraries/gnutls/nix-ssl-cert-file.patch b/pkgs/by-name/gn/gnutls/nix-ssl-cert-file.patch
similarity index 100%
rename from pkgs/development/libraries/gnutls/nix-ssl-cert-file.patch
rename to pkgs/by-name/gn/gnutls/nix-ssl-cert-file.patch
diff --git a/pkgs/development/libraries/gnutls/default.nix b/pkgs/by-name/gn/gnutls/package.nix
similarity index 97%
rename from pkgs/development/libraries/gnutls/default.nix
rename to pkgs/by-name/gn/gnutls/package.nix
index 2cce91e8115d..fc21229d0d35 100644
--- a/pkgs/development/libraries/gnutls/default.nix
+++ b/pkgs/by-name/gn/gnutls/package.nix
@@ -1,6 +1,7 @@
 {
   lib,
   stdenv,
+  buildPackages,
   fetchurl,
   zlib,
   libtasn1,
@@ -8,7 +9,6 @@
   pkg-config,
   perl,
   gmp,
-  autoconf,
   automake,
   libidn2,
   libiconv,
@@ -16,7 +16,7 @@
   unbound,
   dns-root-data,
   gettext,
-  util-linux,
+  util-linuxMinimal,
   cxxBindings ? !stdenv.hostPlatform.isStatic, # tries to link libstdc++.so
   tpmSupport ? false,
   trousers,
@@ -55,6 +55,9 @@ let
     && stdenv.buildPlatform == stdenv.hostPlatform;
 
   inherit (stdenv.hostPlatform) isDarwin;
+
+  # break the cyclic dependency
+  util-linux = util-linuxMinimal;
 in
 
 stdenv.mkDerivation rec {
@@ -161,7 +164,7 @@ stdenv.mkDerivation rec {
     texinfo
   ]
   ++ [
-    autoconf
+    buildPackages.autoconf269
     automake
   ]
   ++ lib.optionals doCheck [
diff --git a/pkgs/by-name/gs/gspell/package.nix b/pkgs/by-name/gs/gspell/package.nix
index e71f3692fc6c..e7fe95307a58 100644
--- a/pkgs/by-name/gs/gspell/package.nix
+++ b/pkgs/by-name/gs/gspell/package.nix
@@ -13,7 +13,7 @@
   mesonEmulatorHook,
   gtk3,
   icu,
-  enchant2,
+  enchant,
   gnome,
 }:
 
@@ -55,7 +55,7 @@ stdenv.mkDerivation rec {
 
   propagatedBuildInputs = [
     # required for pkg-config
-    enchant2
+    enchant
   ];
 
   passthru = {
diff --git a/pkgs/by-name/he/hexchat/package.nix b/pkgs/by-name/he/hexchat/package.nix
index 1834fceda867..2991989c85a4 100644
--- a/pkgs/by-name/he/hexchat/package.nix
+++ b/pkgs/by-name/he/hexchat/package.nix
@@ -1,7 +1,7 @@
 {
   dbus-glib,
   desktop-file-utils,
-  enchant2,
+  enchant_2,
   fetchFromGitHub,
   gtk2,
   isocodes,
@@ -34,7 +34,7 @@ stdenv.mkDerivation rec {
 
   #hexchat and hexchat-text loads enchant spell checking library at run time and so it needs to have route to the path
   postPatch = ''
-    sed -i "s,libenchant-2.so.2,${enchant2}/lib/libenchant-2.so.2,g" src/fe-gtk/sexy-spell-entry.c
+    sed -i "s,libenchant-2.so.2,${enchant_2}/lib/libenchant-2.so.2,g" src/fe-gtk/sexy-spell-entry.c
     sed -i "/flag.startswith('-I')/i if flag.contains('no-such-path')\ncontinue\nendif" plugins/perl/meson.build
     chmod +x meson_post_install.py
     for f in meson_post_install.py \
diff --git a/pkgs/development/libraries/dbus/make-session-conf.xsl b/pkgs/by-name/ma/makeDBusConf/make-session-conf.xsl
similarity index 100%
rename from pkgs/development/libraries/dbus/make-session-conf.xsl
rename to pkgs/by-name/ma/makeDBusConf/make-session-conf.xsl
diff --git a/pkgs/development/libraries/dbus/make-system-conf.xsl b/pkgs/by-name/ma/makeDBusConf/make-system-conf.xsl
similarity index 100%
rename from pkgs/development/libraries/dbus/make-system-conf.xsl
rename to pkgs/by-name/ma/makeDBusConf/make-system-conf.xsl
diff --git a/pkgs/development/libraries/dbus/make-dbus-conf.nix b/pkgs/by-name/ma/makeDBusConf/package.nix
similarity index 100%
rename from pkgs/development/libraries/dbus/make-dbus-conf.nix
rename to pkgs/by-name/ma/makeDBusConf/package.nix
diff --git a/pkgs/development/libraries/audio/rtaudio/default.nix b/pkgs/by-name/rt/rtaudio_5/package.nix
similarity index 96%
rename from pkgs/development/libraries/audio/rtaudio/default.nix
rename to pkgs/by-name/rt/rtaudio_5/package.nix
index 843788a86357..dd142e55f2d1 100644
--- a/pkgs/development/libraries/audio/rtaudio/default.nix
+++ b/pkgs/by-name/rt/rtaudio_5/package.nix
@@ -10,7 +10,7 @@
   pulseaudioSupport ? config.pulseaudio or stdenv.hostPlatform.isLinux,
   libpulseaudio,
   jackSupport ? true,
-  jack,
+  libjack2,
   coreaudioSupport ? stdenv.hostPlatform.isDarwin,
 }:
 
@@ -34,7 +34,7 @@ stdenv.mkDerivation rec {
   buildInputs =
     lib.optional alsaSupport alsa-lib
     ++ lib.optional pulseaudioSupport libpulseaudio
-    ++ lib.optional jackSupport jack;
+    ++ lib.optional jackSupport libjack2;
 
   cmakeFlags = [
     "-DRTAUDIO_API_ALSA=${if alsaSupport then "ON" else "OFF"}"
diff --git a/pkgs/development/libraries/audio/rtmidi/default.nix b/pkgs/by-name/rt/rtmidi/package.nix
similarity index 96%
rename from pkgs/development/libraries/audio/rtmidi/default.nix
rename to pkgs/by-name/rt/rtmidi/package.nix
index fb8d867d96f8..774c754447d3 100644
--- a/pkgs/development/libraries/audio/rtmidi/default.nix
+++ b/pkgs/by-name/rt/rtmidi/package.nix
@@ -8,7 +8,7 @@
   alsaSupport ? stdenv.hostPlatform.isLinux,
   alsa-lib,
   jackSupport ? true,
-  jack,
+  libjack2,
   coremidiSupport ? stdenv.hostPlatform.isDarwin,
 }:
 
@@ -28,7 +28,7 @@ stdenv.mkDerivation rec {
     pkg-config
   ];
 
-  buildInputs = lib.optional alsaSupport alsa-lib ++ lib.optional jackSupport jack;
+  buildInputs = lib.optional alsaSupport alsa-lib ++ lib.optional jackSupport libjack2;
 
   cmakeFlags = [
     "-DRTMIDI_API_ALSA=${if alsaSupport then "ON" else "OFF"}"
diff --git a/pkgs/by-name/sw/sword/package.nix b/pkgs/by-name/sw/sword/package.nix
index 3e9f942466d0..1c0afb3d13fb 100644
--- a/pkgs/by-name/sw/sword/package.nix
+++ b/pkgs/by-name/sw/sword/package.nix
@@ -4,7 +4,7 @@
   fetchurl,
   pkg-config,
   icu,
-  clucene_core,
+  clucene-core,
 
   autoreconfHook,
   bzip2,
@@ -38,7 +38,7 @@ stdenv.mkDerivation (
       icu
     ]
     ++ (lib.optionals stdenv.hostPlatform.isUnix [
-      clucene_core
+      clucene-core
       curl
     ])
     ++ (lib.optionals stdenv.hostPlatform.isWindows [
diff --git a/pkgs/development/haskell-modules/configuration-nix.nix b/pkgs/development/haskell-modules/configuration-nix.nix
index 0484220e09e5..a2ff42270836 100644
--- a/pkgs/development/haskell-modules/configuration-nix.nix
+++ b/pkgs/development/haskell-modules/configuration-nix.nix
@@ -760,7 +760,7 @@ builtins.intersectAttrs super {
   fltkhs = overrideCabal (drv: {
     libraryToolDepends = (drv.libraryToolDepends or [ ]) ++ [ pkgs.buildPackages.autoconf ];
     librarySystemDepends = (drv.librarySystemDepends or [ ]) ++ [
-      pkgs.fltk13
+      pkgs.fltk_1_3
       pkgs.libGL
       pkgs.libjpeg
     ];
diff --git a/pkgs/development/haskell-modules/hackage-packages.nix b/pkgs/development/haskell-modules/hackage-packages.nix
index 9996c4aa1233..c05545e4e5cc 100644
--- a/pkgs/development/haskell-modules/hackage-packages.nix
+++ b/pkgs/development/haskell-modules/hackage-packages.nix
@@ -239746,7 +239746,7 @@ self: {
           Cabal,
           directory,
           filepath,
-          fltk14,
+          fltk_1_4,
           libGL,
           libGLU,
           mtl,
@@ -239775,7 +239775,7 @@ self: {
             text
             vector
           ];
-          librarySystemDepends = [ fltk14 ];
+          librarySystemDepends = [ fltk_1_4 ];
           libraryPkgconfigDepends = [
             libGL
             libGLU
@@ -239800,7 +239800,7 @@ self: {
         }
       )
       {
-        inherit (pkgs) fltk14;
+        inherit (pkgs) fltk_1_4;
         inherit (pkgs) libGL;
         inherit (pkgs) libGLU;
         inherit (pkgs) pkg-config;
diff --git a/pkgs/development/libraries/c-blosc/default.nix b/pkgs/development/libraries/c-blosc/default.nix
deleted file mode 100644
index f5281cf832ab..000000000000
--- a/pkgs/development/libraries/c-blosc/default.nix
+++ /dev/null
@@ -1,5 +0,0 @@
-{ callPackage }:
-{
-  c-blosc = callPackage ./1.nix { };
-  c-blosc2 = callPackage ./2.nix { };
-}
diff --git a/pkgs/development/libraries/webkitgtk/default.nix b/pkgs/development/libraries/webkitgtk/default.nix
index e54a8077d761..2b5b24356104 100644
--- a/pkgs/development/libraries/webkitgtk/default.nix
+++ b/pkgs/development/libraries/webkitgtk/default.nix
@@ -21,7 +21,7 @@
   wayland-protocols,
   wayland-scanner,
   libwebp,
-  enchant2,
+  enchant,
   xorg,
   libxkbcommon,
   libavif,
@@ -141,7 +141,7 @@ clangStdenv.mkDerivation (finalAttrs: {
   buildInputs = [
     at-spi2-core
     cairo # required even when using skia
-    enchant2
+    enchant
     flite
     libavif
     libepoxy
diff --git a/pkgs/development/python-modules/pyenchant/default.nix b/pkgs/development/python-modules/pyenchant/default.nix
index 6024528bb534..3ca3b126b8f3 100644
--- a/pkgs/development/python-modules/pyenchant/default.nix
+++ b/pkgs/development/python-modules/pyenchant/default.nix
@@ -4,7 +4,7 @@
   buildPythonPackage,
   isPy27,
   fetchPypi,
-  enchant2,
+  enchant_2,
 }:
 
 buildPythonPackage rec {
@@ -18,7 +18,7 @@ buildPythonPackage rec {
     sha256 = "sha256-glKIJGtd68lDb5GWdlCXTvDVY2RYUCYZ4yLEdvEoOJE=";
   };
 
-  propagatedBuildInputs = [ enchant2 ];
+  propagatedBuildInputs = [ enchant_2 ];
 
   postPatch =
     let
@@ -33,7 +33,7 @@ buildPythonPackage rec {
       # it "accidentally" work by pulling something from /opt.
       substituteInPlace enchant/_enchant.py                  \
         --replace 'os.environ.get("PYENCHANT_LIBRARY_PATH")' \
-                  "'${enchant2}/lib/libenchant-2${libext}'"  \
+                  "'${enchant_2}/lib/libenchant-2${libext}'"  \
         --replace '/opt/local/lib/' ""
     '';
 
diff --git a/pkgs/top-level/aliases.nix b/pkgs/top-level/aliases.nix
index 4d2f6702247c..983b957f5d2c 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -466,6 +466,8 @@ mapAliases {
   clima = throw "'clima' has been removed, as it has been unmaintained upstream since December 2024, use glow instead"; # Added 2026-01-01
   clipbuzz = throw "clipbuzz has been removed, as it does not build with supported Zig versions"; # Added 2025-08-09
   cloudlogoffline = throw "cloudlogoffline has been removed"; # Added 2025-05-18
+  clucene_core = warnAlias "'clucene_core' has been renamed to 'clucene-core'" clucene-core; # Added 2026-01-12
+  clucene_core_2 = warnAlias "'clucene_core_2' has been renamed to 'clucene-core_2'" clucene-core_2; # Added 2026-01-12
   cockroachdb-bin = throw "'cockroachdb-bin' has been renamed to/replaced by 'cockroachdb'"; # Converted to throw 2025-10-27
   code-browser-gtk2 = throw "'code-browser-gtk2' has been removed, as it was broken since 22.11"; # Added 2025-08-22
   code-browser-gtk = throw "'code-browser-gtk' has been removed, as it was broken since 22.11"; # Added 2025-08-22
@@ -585,6 +587,7 @@ mapAliases {
   EmptyEpsilon = throw "'EmptyEpsilon' has been renamed to/replaced by 'empty-epsilon'"; # Converted to throw 2025-10-27
   emulationstation = throw "emulationstation was removed due to numerous vulnerabilities in freeimage"; # Added 2025-10-23
   emulationstation-de = throw "emulationstation-de was removed due to numerous vulnerabilities in freeimage"; # Added 2025-10-23
+  enchant2 = warnAlias "'enchant2' has been renamed to 'enchant_2'" enchant_2; # Added 2026-01-14
   enyo-doom = throw "'enyo-doom' has been renamed to/replaced by 'enyo-launcher'"; # Converted to throw 2025-10-27
   epapirus-icon-theme = throw "'epapirus-icon-theme' has been removed because 'papirus-icon-theme' no longer supports building with elementaryOS icon support"; # Added 2025-06-15
   eris-go = throw "'eris-go' has been removed due to a hostile upstream moving tags and breaking src FODs"; # Added 2025-09-01
@@ -627,6 +630,10 @@ mapAliases {
   floorp = throw "floorp has been replaced with floorp-bin, as building from upstream sources has become unfeasible starting with version 12.x"; # Added 2025-09-06
   floorp-unwrapped = throw "floorp-unwrapped has been replaced with floorp-bin-unwrapped, as building from upstream sources has become unfeasible starting with version 12.x"; # Added 2025-09-06
   flow-editor = throw "'flow-editor' has been renamed to/replaced by 'flow-control'"; # Converted to throw 2025-10-27
+  fltk13 = warnAlias "'fltk13' has been renamed to 'fltk_1_3'" fltk_1_3; # Added 2026-01-14
+  fltk13-minimal = warnAlias "'fltk13-minimal' has been renamed to 'fltk_1_3-minimal'" fltk_1_3-minimal; # Added 2026-01-14
+  fltk14 = warnAlias "'fltk14' has been renamed to 'fltk_1_4'" fltk_1_4; # Added 2026-01-14
+  fltk14-minimal = warnAlias "'fltk14-minimal' has been renamed to 'fltk_1_4-minimal'" fltk_1_4-minimal; # Added 2026-01-14
   flut-renamer = throw "flut-renamer is unmaintained and has been removed"; # Added 2025-08-26
   flutter324 = throw "flutter324 has been removed because it isn't updated anymore, and no packages in nixpkgs use it. If you still need it, use flutter.mkFlutter to get a custom version"; # Added 2025-10-28
   flutter326 = throw "flutter326 has been removed because it isn't updated anymore, and no packages in nixpkgs use it. If you still need it, use flutter.mkFlutter to get a custom version"; # Added 2025-06-08
@@ -692,6 +699,7 @@ mapAliases {
   gjay = throw "'gjay' has been removed as it is unmaintained upstream"; # Added 2025-05-25
   glabels = throw "'glabels' has been removed because it is no longer maintained. Consider using 'glabels-qt', which is an active fork."; # Added 2025-09-16
   glaxnimate = kdePackages.glaxnimate; # Added 2025-09-17
+  glew110 = warnAlias "'glew110' has been renamed to 'glew_1_10'" glew_1_10; # Added 2026-01-14
   glew-egl = throw "'glew-egl' has been renamed to/replaced by 'glew'"; # Converted to throw 2025-10-27
   glfw-wayland = throw "'glfw-wayland' has been renamed to/replaced by 'glfw'"; # Converted to throw 2025-10-27
   glfw-wayland-minecraft = throw "'glfw-wayland-minecraft' has been renamed to/replaced by 'glfw3-minecraft'"; # Converted to throw 2025-10-27
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 42f288fdd537..d696eda5597e 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -1632,9 +1632,7 @@ with pkgs;
 
   asmrepl = callPackage ../development/interpreters/asmrepl { };
 
-  avahi = callPackage ../development/libraries/avahi { };
-
-  avahi-compat = callPackage ../development/libraries/avahi {
+  avahi-compat = callPackage ../by-name/av/avahi/package.nix {
     withLibdnssdCompat = true;
   };
 
@@ -1719,13 +1717,6 @@ with pkgs;
       '';
     });
 
-  capstone = callPackage ../development/libraries/capstone { };
-  capstone_4 = callPackage ../development/libraries/capstone/4.nix { };
-
-  ceres-solver = callPackage ../development/libraries/ceres-solver {
-    gflags = null; # only required for examples/tests
-  };
-
   cedille = callPackage ../applications/science/logic/cedille {
     inherit (haskellPackages)
       alex
@@ -2562,10 +2553,6 @@ with pkgs;
     inherit (darwin) autoSignDarwinBinariesHook;
   };
 
-  fox = callPackage ../development/libraries/fox { };
-
-  fox_1_6 = callPackage ../development/libraries/fox/fox-1.6.nix { };
-
   fpm = callPackage ../tools/package-management/fpm { };
 
   ferdium = callPackage ../applications/networking/instant-messengers/ferdium {
@@ -3593,13 +3580,7 @@ with pkgs;
 
   rocket = libsForQt5.callPackage ../tools/graphics/rocket { };
 
-  rtaudio = callPackage ../development/libraries/audio/rtaudio {
-    jack = libjack2;
-  };
-
-  rtmidi = callPackage ../development/libraries/audio/rtmidi {
-    jack = libjack2;
-  };
+  rtaudio = rtaudio_5;
 
   mpi = openmpi; # this attribute should used to build MPI applications
   openmodelica = recurseIntoAttrs (callPackage ../applications/science/misc/openmodelica { });
@@ -6579,10 +6560,6 @@ with pkgs;
 
   acl = callPackage ../development/libraries/acl { };
 
-  agg = callPackage ../development/libraries/agg {
-    stdenv = gccStdenv;
-  };
-
   allegro = allegro4;
   allegro4 = callPackage ../development/libraries/allegro { };
   allegro5 = callPackage ../development/libraries/allegro/5.nix { };
@@ -6642,25 +6619,12 @@ with pkgs;
 
   botanEsdm = botan3.override { withEsdm = true; };
 
-  c-ares = callPackage ../development/libraries/c-ares { };
-
-  c-aresMinimal = callPackage ../development/libraries/c-ares {
-    withCMake = false;
-  };
-
-  inherit (callPackages ../development/libraries/c-blosc { })
-    c-blosc
-    c-blosc2
-    ;
+  c-aresMinimal = callPackage ../by-name/c-/c-ares/package.nix { withCMake = false; };
 
   niv = lib.getBin (haskell.lib.compose.justStaticExecutables haskellPackages.niv);
 
   ormolu = lib.getBin (haskell.lib.compose.justStaticExecutables haskellPackages.ormolu);
 
-  cctag = callPackage ../development/libraries/cctag {
-    stdenv = clangStdenv;
-  };
-
   ceedling = callPackage ../development/tools/ceedling { };
 
   celt = callPackage ../development/libraries/celt { };
@@ -6679,9 +6643,7 @@ with pkgs;
     ]
   );
 
-  clucene_core_2 = callPackage ../development/libraries/clucene-core/2.x.nix { };
-
-  clucene_core = clucene_core_2;
+  clucene-core = clucene-core_2;
 
   codecserver = callPackage ../applications/audio/codecserver {
     protobuf = protobuf_21;
@@ -6713,14 +6675,6 @@ with pkgs;
   db60 = callPackage ../development/libraries/db/db-6.0.nix { };
   db62 = callPackage ../development/libraries/db/db-6.2.nix { };
 
-  dbus = callPackage ../development/libraries/dbus { };
-
-  makeDBusConf = callPackage ../development/libraries/dbus/make-dbus-conf.nix { };
-
-  draco = callPackage ../development/libraries/draco {
-    tinygltf = callPackage ../development/libraries/draco/tinygltf.nix { };
-  };
-
   # Multi-arch "drivers" which we want to build for i686.
   driversi686Linux = recurseIntoAttrs {
     inherit (pkgsi686Linux)
@@ -6734,15 +6688,9 @@ with pkgs;
       ;
   };
 
-  eccodes = callPackage ../development/libraries/eccodes {
-    pythonPackages = python3Packages;
-    stdenv = if stdenv.hostPlatform.isDarwin then gccStdenv else stdenv;
-  };
-
   vapoursynth-editor = libsForQt5.callPackage ../by-name/va/vapoursynth/editor.nix { };
 
-  enchant2 = callPackage ../development/libraries/enchant/2.x.nix { };
-  enchant = enchant2;
+  enchant = enchant_2;
 
   factorPackages-0_99 = callPackage ./factor-packages.nix {
     factor-unwrapped = callPackage ../development/compilers/factor-lang/0.99.nix { };
@@ -6764,17 +6712,6 @@ with pkgs;
   factor-lang-0_101 = factorPackages-0_101.factor-lang;
   factor-lang = factor-lang-0_101;
 
-  farstream = callPackage ../development/libraries/farstream {
-    inherit (gst_all_1)
-      gstreamer
-      gst-plugins-base
-      gst-plugins-good
-      gst-plugins-bad
-      gst-libav
-      ;
-    autoreconfHook = buildPackages.autoreconfHook269;
-  };
-
   inherit (callPackage ../development/libraries/ffmpeg { })
     ffmpeg_4
     ffmpeg_4-headless
@@ -6803,23 +6740,21 @@ with pkgs;
   };
   fftwMpi = fftw.override { enableMpi = true; };
 
-  fltk13 = callPackage ../development/libraries/fltk { };
-  fltk14 = callPackage ../development/libraries/fltk/1.4.nix { };
-  fltk13-minimal = fltk13.override {
+  fltk_1_3-minimal = fltk_1_3.override {
     withGL = false;
     withCairo = false;
     withExamples = false;
     withDocs = false;
   };
-  fltk14-minimal = fltk14.override {
+  fltk_1_4-minimal = fltk_1_4.override {
     withGL = false;
     withCairo = false;
     withPango = false;
     withExamples = false;
     withDocs = false;
   };
-  fltk = fltk13;
-  fltk-minimal = fltk13-minimal;
+  fltk = fltk_1_3;
+  fltk-minimal = fltk_1_3-minimal;
 
   inherit (callPackages ../development/libraries/fmt { })
     fmt_9
@@ -6830,9 +6765,6 @@ with pkgs;
 
   fmt = fmt_12;
 
-  fplll = callPackage ../development/libraries/fplll { };
-  fplll_20160331 = callPackage ../development/libraries/fplll/20160331.nix { };
-
   freeipa = callPackage ../os-specific/linux/freeipa {
     # NOTE: freeipa and sssd need to be built with the same version of python
     kerberos = krb5.override {
@@ -6850,53 +6782,32 @@ with pkgs;
 
   makeFontsCache = callPackage ../development/libraries/fontconfig/make-fonts-cache.nix { };
 
-  gamenetworkingsockets = callPackage ../development/libraries/gamenetworkingsockets {
-    protobuf = protobuf_21;
-  };
-
   gamt = callPackage ../by-name/am/amtterm/package.nix { withGamt = true; };
 
-  gcr = callPackage ../development/libraries/gcr { };
-
-  gcr_4 = callPackage ../development/libraries/gcr/4.nix { };
-
   gecode_3 = callPackage ../development/libraries/gecode/3.nix { };
   gecode_6 = qt5.callPackage ../development/libraries/gecode { };
   gecode = gecode_6;
 
-  gegl = callPackage ../development/libraries/gegl {
-    openexr = openexr_2;
-  };
-
   geoclue2-with-demo-agent = geoclue2.override { withDemoAgent = true; };
 
-  geoipWithDatabase = makeOverridable (callPackage ../development/libraries/geoip) {
+  geoipWithDatabase = makeOverridable (callPackage ../by-name/ge/geoip/package.nix) {
     drvName = "geoip-tools";
     geoipDatabase = geolite-legacy;
   };
 
-  geoip = callPackage ../development/libraries/geoip { };
-
   gettext = callPackage ../development/libraries/gettext { };
 
   gdalMinimal = gdal.override {
     useMinimalFeatures = true;
   };
 
-  gdcm = callPackage ../development/libraries/gdcm {
-    inherit (darwin) DarwinTools;
-  };
-
   ghp-import = with python3Packages; toPythonApplication ghp-import;
 
   ghcid = haskellPackages.ghcid.bin;
 
   graphia = qt6Packages.callPackage ../applications/science/misc/graphia { };
 
-  glew = callPackage ../development/libraries/glew { };
-  glew110 = callPackage ../development/libraries/glew/1.10.nix { };
   glfw = glfw3;
-  glfw2 = callPackage ../development/libraries/glfw/2.x.nix { };
 
   glfw3-minecraft = callPackage ../by-name/gl/glfw3/package.nix {
     withMinecraftPatch = true;
@@ -7061,11 +6972,6 @@ with pkgs;
 
   gst_all_1 = recurseIntoAttrs (callPackage ../development/libraries/gstreamer { });
 
-  gnutls = callPackage ../development/libraries/gnutls {
-    util-linux = util-linuxMinimal; # break the cyclic dependency
-    autoconf = buildPackages.autoconf269;
-  };
-
   grantlee = libsForQt5.callPackage ../development/libraries/grantlee { };
 
   glib = callPackage ../by-name/gl/glib/package.nix (
@@ -7081,33 +6987,17 @@ with pkgs;
     }
   );
 
-  glibmm = callPackage ../development/libraries/glibmm { };
-
-  glibmm_2_68 = callPackage ../development/libraries/glibmm/2.68.nix { };
-
   glirc = haskell.lib.compose.justStaticExecutables haskellPackages.glirc;
 
   # Not moved to aliases while we decide if we should split the package again.
   atk = at-spi2-core;
 
-  atkmm = callPackage ../development/libraries/atkmm { };
-
-  atkmm_2_36 = callPackage ../development/libraries/atkmm/2.36.nix { };
-
-  cairomm = callPackage ../development/libraries/cairomm { };
-
-  cairomm_1_16 = callPackage ../development/libraries/cairomm/1.16.nix { };
-
   pangomm = callPackage ../development/libraries/pangomm { };
 
   pangomm_2_48 = callPackage ../development/libraries/pangomm/2.48.nix { };
 
   pangomm_2_42 = callPackage ../development/libraries/pangomm/2.42.nix { };
 
-  gdk-pixbuf = callPackage ../development/libraries/gdk-pixbuf { };
-
-  gdk-pixbuf-xlib = callPackage ../development/libraries/gdk-pixbuf/xlib.nix { };
-
   gtk2 = callPackage ../development/libraries/gtk/2.x.nix { };
 
   gtk2-x11 = gtk2.override {
@@ -7994,9 +7884,6 @@ with pkgs;
     protobuf_21
     ;
 
-  flatbuffers = callPackage ../development/libraries/flatbuffers { };
-  flatbuffers_23 = callPackage ../development/libraries/flatbuffers/23.nix { };
-
   nanopbMalloc = callPackage ../by-name/na/nanopb/package.nix { enableMalloc = true; };
 
   pth = if stdenv.hostPlatform.isMusl then npth else gnupth;
@@ -8811,8 +8698,6 @@ with pkgs;
   };
   cassandra = cassandra_4;
 
-  cassandra-cpp-driver = callPackage ../development/libraries/cassandra-cpp-driver/default.nix { };
-
   apache-jena = callPackage ../servers/nosql/apache-jena/binary.nix {
     java = jre;
   };
@@ -11644,7 +11529,7 @@ with pkgs;
   };
 
   rakarrack = callPackage ../applications/audio/rakarrack {
-    fltk = fltk13;
+    fltk = fltk_1_3;
   };
 
   rawtherapee = callPackage ../applications/graphics/rawtherapee {
@@ -12089,7 +11974,7 @@ with pkgs;
   );
 
   virtualglLib = callPackage ../tools/X11/virtualgl/lib.nix {
-    fltk = fltk13;
+    fltk = fltk_1_3;
   };
 
   virtualgl = callPackage ../tools/X11/virtualgl {
@@ -13924,7 +13809,7 @@ with pkgs;
   yaziPlugins = recurseIntoAttrs (callPackage ../by-name/ya/yazi/plugins { });
 
   dillo = callPackage ../by-name/di/dillo/package.nix {
-    fltk = fltk13;
+    fltk = fltk_1_3;
   };
 
   libkazv = callPackage ../by-name/li/libkazv/package.nix {
diff --git a/pkgs/top-level/php-packages.nix b/pkgs/top-level/php-packages.nix
index bd805eef0f1b..b11347318543 100644
--- a/pkgs/top-level/php-packages.nix
+++ b/pkgs/top-level/php-packages.nix
@@ -11,7 +11,7 @@
   bzip2,
   curl,
   cyrus_sasl,
-  enchant2,
+  enchant,
   freetds,
   gd,
   gettext,
@@ -450,7 +450,7 @@ lib.makeScope pkgs.newScope (
             }
             {
               name = "enchant";
-              buildInputs = [ enchant2 ];
+              buildInputs = [ enchant ];
               configureFlags = [ "--with-enchant" ];
               doCheck = false;
             }
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 4976bb2eb2e8..85382c4d8fad 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -4775,7 +4775,7 @@ self: super: with self; {
   eccodes = toPythonModule (
     pkgs.eccodes.override {
       enablePython = true;
-      pythonPackages = self;
+      python3Packages = self;
     }
   );
 
@@ -13377,7 +13377,7 @@ self: super: with self; {
 
   pyemvue = callPackage ../development/python-modules/pyemvue { };
 
-  pyenchant = callPackage ../development/python-modules/pyenchant { inherit (pkgs) enchant2; };
+  pyenchant = callPackage ../development/python-modules/pyenchant { inherit (pkgs) enchant_2; };
 
   pyenphase = callPackage ../development/python-modules/pyenphase { };