diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index e9234d92ec89..5f919dbf7855 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -128,7 +128,6 @@ in
   ferm = handleTest ./ferm.nix {};
   firefox = handleTest ./firefox.nix { firefoxPackage = pkgs.firefox; };
   firefox-esr    = handleTest ./firefox.nix { firefoxPackage = pkgs.firefox-esr; }; # used in `tested` job
-  firefox-esr-78 = handleTest ./firefox.nix { firefoxPackage = pkgs.firefox-esr-78; };
   firefox-esr-91 = handleTest ./firefox.nix { firefoxPackage = pkgs.firefox-esr-91; };
   firejail = handleTest ./firejail.nix {};
   firewall = handleTest ./firewall.nix {};
diff --git a/pkgs/applications/networking/browsers/firefox/common.nix b/pkgs/applications/networking/browsers/firefox/common.nix
index a1a215aefcbd..c99d1c10a12c 100644
--- a/pkgs/applications/networking/browsers/firefox/common.nix
+++ b/pkgs/applications/networking/browsers/firefox/common.nix
@@ -5,15 +5,15 @@
 
 { lib, stdenv, pkg-config, pango, perl, python3, zip
 , libjpeg, zlib, dbus, dbus-glib, bzip2, xorg
-, freetype, fontconfig, file, nspr, nss, nss_3_53
+, freetype, fontconfig, file, nspr, nss
 , yasm, libGLU, libGL, sqlite, unzip, makeWrapper
 , hunspell, libevent, libstartup_notification
 , libvpx_1_8
 , icu69, libpng, glib, pciutils
-, autoconf213, which, gnused, rustPackages, rustPackages_1_45
+, autoconf213, which, gnused, rustPackages
 , rust-cbindgen, nodejs, nasm, fetchpatch
 , gnum4
-, gtk2, gtk3, wrapGAppsHook
+, gtk3, wrapGAppsHook
 , debugBuild ? false
 
 ### optionals
@@ -91,20 +91,16 @@ let
             then "/Applications/${binaryNameCapitalized}.app/Contents/MacOS"
             else "/bin";
 
-  # 78 ESR won't build with rustc 1.47
-  inherit (if lib.versionAtLeast version "82" then rustPackages else rustPackages_1_45)
-    rustc cargo;
+  inherit (rustPackages) rustc cargo;
 
   # Darwin's stdenv provides the default llvmPackages version, match that since
   # clang LTO on Darwin is broken so the stdenv is not being changed.
   # Target the LLVM version that rustc -Vv reports it is built with for LTO.
-  # rustPackages_1_45 -> LLVM 10, rustPackages -> LLVM 11
   llvmPackages0 =
-    /**/ if stdenv.isDarwin
+    if stdenv.isDarwin
       then buildPackages.llvmPackages
-    else if lib.versionAtLeast rustc.llvm.version "11"
-      then buildPackages.llvmPackages_11
-    else buildPackages.llvmPackages_10;
+    else rustc.llvmPackages;
+
   # Force the use of lld and other llvm tools for LTO
   llvmPackages = llvmPackages0.override {
     bootBintoolsNoLibc = null;
@@ -117,8 +113,6 @@ let
                 then overrideCC stdenv llvmPackages.clangUseLLVM
                 else stdenv;
 
-  nss_pkg = if lib.versionOlder version "83" then nss_3_53 else nss;
-
   # --enable-release adds -ffunction-sections & LTO that require a big amount of
   # RAM and the 32-bit memory space cannot handle that linking
   # We also disable adding "-g" for easier linking
@@ -135,27 +129,9 @@ buildStdenv.mkDerivation ({
 
   patches = [
   ] ++
-  lib.optional (lib.versionOlder version "86") ./env_var_for_system_dir-ff85.patch ++
   lib.optional (lib.versionAtLeast version "86") ./env_var_for_system_dir-ff86.patch ++
-  lib.optional (lib.versionOlder version "83") ./no-buildconfig-ffx76.patch ++
   lib.optional (lib.versionAtLeast version "90") ./no-buildconfig-ffx90.patch ++
-  lib.optional (ltoSupport && lib.versionOlder version "84") ./lto-dependentlibs-generation-ffx83.patch ++
-  lib.optional (ltoSupport && lib.versionAtLeast version "84" && lib.versionOlder version "86")
-    (fetchpatch {
-      url = "https://hg.mozilla.org/mozilla-central/raw-rev/fdff20c37be3";
-      sha256 = "135n9brliqy42lj3nqgb9d9if7x6x9nvvn0z4anbyf89bikixw48";
-    })
-
-  # This patch adds pipewire support for the ESR release
-  ++ lib.optional (pipewireSupport && lib.versionOlder version "83")
-    (fetchpatch {
-      # https://src.fedoraproject.org/rpms/firefox/blob/master/f/firefox-pipewire-0-3.patch
-      url = "https://src.fedoraproject.org/rpms/firefox/raw/e99b683a352cf5b2c9ff198756859bae408b5d9d/f/firefox-pipewire-0-3.patch";
-      sha256 = "0qc62di5823r7ly2lxkclzj9rhg2z7ms81igz44nv0fzv3dszdab";
-    })
-
-  ++ patches;
-
+  patches;
 
   # Ignore trivial whitespace changes in patches, this fixes compatibility of
   # ./env_var_for_system_dir.patch with Firefox >=65 without having to track
@@ -163,7 +139,7 @@ buildStdenv.mkDerivation ({
   patchFlags = [ "-p1" "-l" ];
 
   buildInputs = [
-    gtk3 perl zip libjpeg zlib bzip2
+    gnum4 gtk3 perl zip libjpeg zlib bzip2
     dbus dbus-glib pango freetype fontconfig xorg.libXi xorg.libXcursor
     xorg.libX11 xorg.libXrender xorg.libXft xorg.libXt file
     xorg.pixman yasm libGLU libGL
@@ -177,7 +153,7 @@ buildStdenv.mkDerivation ({
     # yasm can potentially be removed in future versions
     # https://bugzilla.mozilla.org/show_bug.cgi?id=1501796
     # https://groups.google.com/forum/#!msg/mozilla.dev.platform/o-8levmLU80/SM_zQvfzCQAJ
-    nspr nss_pkg
+    nspr nss
   ]
   ++ lib.optional  alsaSupport alsa-lib
   ++ lib.optional  pulseaudioSupport libpulseaudio # only headers are needed
@@ -185,11 +161,9 @@ buildStdenv.mkDerivation ({
   ++ lib.optionals waylandSupport [ libxkbcommon libdrm ]
   ++ lib.optional  pipewireSupport pipewire
   ++ lib.optional  jemallocSupport jemalloc
-  ++ lib.optional  (lib.versionAtLeast version "82") gnum4
   ++ lib.optionals buildStdenv.isDarwin [ CoreMedia ExceptionHandling Kerberos
                                           AVFoundation MediaToolbox CoreLocation
-                                          Foundation libobjc AddressBook cups ]
-  ++ lib.optional  (lib.versionOlder version "90") gtk2;
+                                          Foundation libobjc AddressBook cups ];
 
   NIX_LDFLAGS = lib.optionalString ltoSupport ''
     -rpath ${llvmPackages.libunwind.out}/lib
@@ -201,22 +175,7 @@ buildStdenv.mkDerivation ({
     rm -rf obj-x86_64-pc-linux-gnu
     substituteInPlace toolkit/xre/glxtest.cpp \
       --replace 'dlopen("libpci.so' 'dlopen("${pciutils}/lib/libpci.so'
-  '' + lib.optionalString (pipewireSupport && lib.versionOlder version "83") ''
-    # substitute the /usr/include/ lines for the libraries that pipewire provides.
-    # The patch we pick from fedora only contains the generated moz.build files
-    # which hardcode the dependency paths instead of running pkg_config.
-    substituteInPlace \
-      media/webrtc/trunk/webrtc/modules/desktop_capture/desktop_capture_generic_gn/moz.build \
-      --replace /usr/include ${pipewire.dev}/include
-  '' + lib.optionalString (lib.versionAtLeast version "80" && lib.versionOlder version "81") ''
-    substituteInPlace dom/system/IOUtils.h \
-      --replace '#include "nspr/prio.h"'          '#include "prio.h"'
-
-    substituteInPlace dom/system/IOUtils.cpp \
-      --replace '#include "nspr/prio.h"'          '#include "prio.h"' \
-      --replace '#include "nspr/private/pprio.h"' '#include "private/pprio.h"' \
-      --replace '#include "nspr/prtypes.h"'       '#include "prtypes.h"'
-  '';
+ '';
 
   nativeBuildInputs =
     [
diff --git a/pkgs/applications/networking/browsers/firefox/env_var_for_system_dir-ff85.patch b/pkgs/applications/networking/browsers/firefox/env_var_for_system_dir-ff85.patch
deleted file mode 100644
index 18d31356989a..000000000000
--- a/pkgs/applications/networking/browsers/firefox/env_var_for_system_dir-ff85.patch
+++ /dev/null
@@ -1,6 +0,0 @@
---- a/toolkit/xre/nsXREDirProvider.cpp        2019-02-28 21:00:14.157543388 +0100
-+++ b/toolkit/xre/nsXREDirProvider.cpp   2019-02-28 21:01:28.731128320 +0100
-@@ -302 +302,2 @@
--  rv = NS_NewNativeLocalFile(dirname, false, getter_AddRefs(localDir));
-+  const char* pathVar = PR_GetEnv("MOZ_SYSTEM_DIR");
-+  rv = NS_NewNativeLocalFile((pathVar && *pathVar) ? nsDependentCString(pathVar) : reinterpret_cast<const nsCString&>(dirname), false, getter_AddRefs(localDir));
diff --git a/pkgs/applications/networking/browsers/firefox/lto-dependentlibs-generation-ffx83.patch b/pkgs/applications/networking/browsers/firefox/lto-dependentlibs-generation-ffx83.patch
deleted file mode 100644
index b6f1b81fa9fe..000000000000
--- a/pkgs/applications/networking/browsers/firefox/lto-dependentlibs-generation-ffx83.patch
+++ /dev/null
@@ -1,45 +0,0 @@
---- a/toolkit/library/build/dependentlibs.py
-+++ b/toolkit/library/build/dependentlibs.py
-@@ -36,26 +36,17 @@ def dependentlibs_win32_objdump(lib):
-     proc.wait()
-     return deps
- 
--def dependentlibs_readelf(lib):
-+def dependentlibs_elf_objdump(lib):
-     '''Returns the list of dependencies declared in the given ELF .so'''
--    proc = subprocess.Popen([substs.get('TOOLCHAIN_PREFIX', '') + 'readelf', '-d', lib], stdout = subprocess.PIPE,
-+    proc = subprocess.Popen([substs['LLVM_OBJDUMP'], '--private-headers', lib], stdout = subprocess.PIPE,
-                             universal_newlines=True)
-     deps = []
-     for line in proc.stdout:
--        # Each line has the following format:
--        #  tag (TYPE)          value
--        # or with BSD readelf:
--        #  tag TYPE            value
--        # Looking for NEEDED type entries
--        tmp = line.split(' ', 3)
--        if len(tmp) > 3 and 'NEEDED' in tmp[2]:
--            # NEEDED lines look like:
--            # 0x00000001 (NEEDED)             Shared library: [libname]
--            # or with BSD readelf:
--            # 0x00000001 NEEDED               Shared library: [libname]
--            match = re.search('\[(.*)\]', tmp[3])
--            if match:
--                deps.append(match.group(1))
-+        # We are looking for lines with the format:
-+        #   NEEDED             libname
-+        tmp = line.split()
-+        if len(tmp) == 2 and tmp[0] == 'NEEDED':
-+            deps.append(tmp[1])
-     proc.wait()
-     return deps
- 
-@@ -110,7 +101,7 @@ def gen_list(output, lib):
-     libpaths = [os.path.join(substs['DIST'], 'bin')]
-     binary_type = get_type(lib)
-     if binary_type == ELF:
--        func = dependentlibs_readelf
-+        func = dependentlibs_elf_objdump
-     elif binary_type == MACHO:
-         func = dependentlibs_mac_objdump
-     else:
diff --git a/pkgs/applications/networking/browsers/firefox/no-buildconfig-ffx76.patch b/pkgs/applications/networking/browsers/firefox/no-buildconfig-ffx76.patch
deleted file mode 100644
index 3530954ea5c5..000000000000
--- a/pkgs/applications/networking/browsers/firefox/no-buildconfig-ffx76.patch
+++ /dev/null
@@ -1,24 +0,0 @@
-Remove about:buildconfig.  If used as-is, it would add unnecessary runtime dependencies.
-diff -ur firefox-65.0-orig/docshell/base/nsAboutRedirector.cpp firefox-65.0/docshell/base/nsAboutRedirector.cpp
---- firefox-76.0.orig/docshell/base/nsAboutRedirector.cpp       2020-05-03 19:01:29.926544735 +0200
-+++ firefox-76.0/docshell/base/nsAboutRedirector.cpp    2020-05-03 19:12:00.845035570 +0200
-@@ -62,8 +62,6 @@
-     {"about", "chrome://global/content/aboutAbout.html", 0},
-     {"addons", "chrome://mozapps/content/extensions/extensions.xhtml",
-      nsIAboutModule::ALLOW_SCRIPT},
--    {"buildconfig", "chrome://global/content/buildconfig.html",
--     nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT},
-     {"checkerboard", "chrome://global/content/aboutCheckerboard.html",
-      nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT |
-          nsIAboutModule::ALLOW_SCRIPT},
-diff -ur firefox-65.0-orig/toolkit/content/jar.mn firefox-65.0/toolkit/content/jar.mn
---- firefox-65.0-orig/toolkit/content/jar.mn    2019-01-23 00:48:35.033372506 +0100
-+++ firefox-65.0/toolkit/content/jar.mn 2019-01-23 00:50:45.126565924 +0100
-@@ -36,7 +36,6 @@
-    content/global/plugins.css
-    content/global/browser-child.js
-    content/global/browser-content.js
--*   content/global/buildconfig.html
-    content/global/buildconfig.css
-    content/global/contentAreaUtils.js
-    content/global/datepicker.xhtml
diff --git a/pkgs/applications/networking/browsers/firefox/packages.nix b/pkgs/applications/networking/browsers/firefox/packages.nix
index 80750b966c15..d1cbe5d44732 100644
--- a/pkgs/applications/networking/browsers/firefox/packages.nix
+++ b/pkgs/applications/networking/browsers/firefox/packages.nix
@@ -7,10 +7,10 @@ in
 rec {
   firefox = common rec {
     pname = "firefox";
-    version = "93.0";
+    version = "94.0";
     src = fetchurl {
       url = "mirror://mozilla/firefox/releases/${version}/source/firefox-${version}.source.tar.xz";
-      sha512 = "b29890e331819d47201b599b9feaaa7eaa0b02088fcbf980efc4f289d43da4f73970bf35ba2f763a2a892fd5318deb68cb9a66e71e9bc0c603642434c7e32e91";
+      sha512 = "5eb65450a0f1842d28d73235f3ef95fa1dbf8cf1467c354f13df51313bd227aaf5a48b741ee49b13378aaaf054bff52004c1dd5a274eddef4a3cf1b913ef7071";
     };
 
     meta = {
@@ -32,10 +32,10 @@ rec {
 
   firefox-esr-91 = common rec {
     pname = "firefox-esr";
-    version = "91.2.0esr";
+    version = "91.3.0esr";
     src = fetchurl {
       url = "mirror://mozilla/firefox/releases/${version}/source/firefox-${version}.source.tar.xz";
-      sha512 = "f4cff7e43ff9927cbab3f02d37d360ee8bb0dbe988e280cb0638ee67bfe3c76e3a0469336de1b212fba66c958d58594b1739aafee1ebb84695d098c1e5c77b9d";
+      sha512 = "7cf6efd165acc134bf576715580c103a2fc10ab928ede4c18f69908c62a04eb0f60affa8ceafd5883b393c31b85cae6821d0ae063c9e78117456d475947deaa9";
     };
 
     meta = {
@@ -54,29 +54,4 @@ rec {
       versionSuffix = "esr";
     };
   };
-
-  firefox-esr-78 = common rec {
-    pname = "firefox-esr";
-    version = "78.15.0esr";
-    src = fetchurl {
-      url = "mirror://mozilla/firefox/releases/${version}/source/firefox-${version}.source.tar.xz";
-      sha512 = "ac3de735b246ce4f0e1619cd2664321ffa374240ce6843e785d79a350dc30c967996bbcc5e3b301cb3d822ca981cbea116758fc4122f1738d75ddfd1165b6378";
-    };
-
-    meta = {
-      description = "A web browser built from Firefox Extended Support Release source tree";
-      homepage = "http://www.mozilla.com/en-US/firefox/";
-      maintainers = with lib.maintainers; [ eelco hexa ];
-      platforms = lib.platforms.unix;
-      badPlatforms = lib.platforms.darwin;
-      broken = stdenv.buildPlatform.is32bit; # since Firefox 60, build on 32-bit platforms fails with "out of memory".
-                                             # not in `badPlatforms` because cross-compilation on 64-bit machine might work.
-      license = lib.licenses.mpl20;
-    };
-    tests = [ nixosTests.firefox-esr-78 ];
-    updateScript = callPackage ./update.nix {
-      attrPath = "firefox-esr-78-unwrapped";
-      versionSuffix = "esr";
-    };
-  };
 }
diff --git a/pkgs/applications/networking/mailreaders/thunderbird/no-buildconfig-78.patch b/pkgs/applications/networking/mailreaders/thunderbird/no-buildconfig-78.patch
deleted file mode 100644
index 98b40d83d62b..000000000000
--- a/pkgs/applications/networking/mailreaders/thunderbird/no-buildconfig-78.patch
+++ /dev/null
@@ -1,13 +0,0 @@
-Remove about:buildconfig.  If used as-is, it would add unnecessary runtime dependencies.
---- a/comm/mail/base/jar.mn
-+++ b/comm/mail/base/jar.mn
-@@ -119,9 +119,7 @@
- % override chrome://mozapps/content/profile/profileDowngrade.js chrome://messenger/content/profileDowngrade.js
- % override chrome://mozapps/content/profile/profileDowngrade.xhtml chrome://messenger/content/profileDowngrade.xhtml
- 
--*   content/messenger/buildconfig.html              (content/buildconfig.html)
-     content/messenger/buildconfig.css               (content/buildconfig.css)
--% override chrome://global/content/buildconfig.html chrome://messenger/content/buildconfig.html
- % override chrome://global/content/buildconfig.css chrome://messenger/content/buildconfig.css
- 
- # L10n resources and overrides.
diff --git a/pkgs/applications/networking/mailreaders/thunderbird/packages.nix b/pkgs/applications/networking/mailreaders/thunderbird/packages.nix
index fa2c5fd0fb8c..9c0359ea558c 100644
--- a/pkgs/applications/networking/mailreaders/thunderbird/packages.nix
+++ b/pkgs/applications/networking/mailreaders/thunderbird/packages.nix
@@ -34,32 +34,4 @@ rec {
       attrPath = "thunderbird-unwrapped";
     };
   };
-
-  thunderbird-78 = common rec {
-    pname = "thunderbird";
-    version = "78.14.0";
-    application = "comm/mail";
-    binaryName = pname;
-    src = fetchurl {
-      url = "mirror://mozilla/thunderbird/releases/${version}/source/thunderbird-${version}.source.tar.xz";
-      sha512 = "0zan30jvv45pd6i59l2kfyfjwivqk5qq6vyf77xhss2dk8qhk3mfrfxpfbkrab676l14b9hs09nr6ni1h1iwn82zx5k7fx5x8sh5dx6";
-    };
-    patches = [
-      ./no-buildconfig-78.patch
-    ];
-
-    meta = with lib; {
-      description = "A full-featured e-mail client";
-      homepage = "https://thunderbird.net/";
-      maintainers = with maintainers; [ eelco lovesegfault pierron vcunat ];
-      platforms = platforms.unix;
-      badPlatforms = platforms.darwin;
-      broken = stdenv.buildPlatform.is32bit; # since Firefox 60, build on 32-bit platforms fails with "out of memory".
-                                             # not in `badPlatforms` because cross-compilation on 64-bit machine might work.
-      license = licenses.mpl20;
-    };
-    updateScript = callPackage ./update.nix {
-      attrPath = "thunderbird-78-unwrapped";
-    };
-  };
 }
diff --git a/pkgs/development/compilers/rust/1_45.nix b/pkgs/development/compilers/rust/1_45.nix
deleted file mode 100644
index 2c695f1844dc..000000000000
--- a/pkgs/development/compilers/rust/1_45.nix
+++ /dev/null
@@ -1,54 +0,0 @@
-# New rust versions should first go to staging.
-# Things to check after updating:
-# 1. Rustc should produce rust binaries on x86_64-linux, aarch64-linux and x86_64-darwin:
-#    i.e. nix-shell -p fd or @GrahamcOfBorg build fd on github
-#    This testing can be also done by other volunteers as part of the pull
-#    request review, in case platforms cannot be covered.
-# 2. The LLVM version used for building should match with rust upstream.
-# 3. Firefox and Thunderbird should still build on x86_64-linux.
-
-{ stdenv, lib
-, buildPackages
-, newScope, callPackage
-, CoreFoundation, Security, SystemConfiguration
-, pkgsBuildTarget, pkgsBuildBuild, pkgsBuildHost
-, makeRustPlatform
-, llvmPackages_5, llvm_10
-} @ args:
-
-import ./default.nix {
-  rustcVersion = "1.45.2";
-  rustcSha256 = "0273a1g3f59plyi1n0azf21qjzwml1yqdnj5z472crz37qggr8xp";
-
-  llvmSharedForBuild = pkgsBuildBuild.llvmPackages_10.libllvm.override { enableSharedLibraries = true; };
-  llvmSharedForHost = pkgsBuildHost.llvmPackages_10.libllvm.override { enableSharedLibraries = true; };
-  llvmSharedForTarget = pkgsBuildTarget.llvmPackages_10.libllvm.override { enableSharedLibraries = true; };
-
-  llvmBootstrapForDarwin = llvmPackages_5;
-
-  # For use at runtime
-  llvmShared = llvm_10.override { enableSharedLibraries = true; };
-
-  # Note: the version MUST be one version prior to the version we're
-  # building
-  bootstrapVersion = "1.44.1";
-
-  # fetch hashes by running `print-hashes.sh ${bootstrapVersion}`
-  bootstrapHashes = {
-    i686-unknown-linux-gnu = "e69689b0a1b66599cf83e7dd54f839419007e44376195e93e301a3175da3d854";
-    x86_64-unknown-linux-gnu = "a41df89a461a580536aeb42755e43037556fba2e527dd13a1e1bb0749de28202";
-    x86_64-unknown-linux-musl = "7eeef2b7488ee96015db10bc52c43f6e023debc9a955ccb8efb382522bf35be9";
-    arm-unknown-linux-gnueabihf = "ea18ccdfb62a153c2d43d013fdec56993cc9267f1cdc6f3834df8a2b9b468f08";
-    armv7-unknown-linux-gnueabihf = "d44294732cf268ea84908f1135f574ab9489132a332eaa9d5bda547374b15d54";
-    aarch64-unknown-linux-gnu = "a2d74ebeec0b6778026b6c37814cdc91d14db3b0d8b6d69d036216f4d9cf7e49";
-    x86_64-apple-darwin = "a5464e7bcbce9647607904a4afa8362382f1fc55d39e7bbaf4483ac00eb5d56a";
-    powerpc64le-unknown-linux-gnu = "22deeca259459db31065af7c862fcab7fbfb623200520c65002ed2ba93d87ad2";
-  };
-
-  selectRustPackage = pkgs: pkgs.rust_1_45;
-
-  rustcPatches = [
-  ];
-}
-
-(builtins.removeAttrs args [ "fetchpatch" "pkgsBuildHost" "llvmPackages_5" "llvm_10" ])
diff --git a/pkgs/development/compilers/rust/1_55.nix b/pkgs/development/compilers/rust/1_55.nix
index edd1f538e398..85a8b65b11a1 100644
--- a/pkgs/development/compilers/rust/1_55.nix
+++ b/pkgs/development/compilers/rust/1_55.nix
@@ -32,6 +32,9 @@ import ./default.nix {
   # For use at runtime
   llvmShared = llvm_12.override { enableSharedLibraries = true; };
 
+  # Expose llvmPackages used for rustc from rustc via passthru for LTO in Firefox
+  llvmPackagesForBuild = pkgsBuildBuild.llvmPackages_12;
+
   # Note: the version MUST be one version prior to the version we're
   # building
   bootstrapVersion = "1.54.0";
diff --git a/pkgs/development/compilers/rust/default.nix b/pkgs/development/compilers/rust/default.nix
index 7912055db624..59420477119c 100644
--- a/pkgs/development/compilers/rust/default.nix
+++ b/pkgs/development/compilers/rust/default.nix
@@ -10,6 +10,7 @@
 , llvmSharedForBuild
 , llvmSharedForHost
 , llvmSharedForTarget
+, llvmPackagesForBuild # Exposed through rustc for LTO in Firefox
 }:
 { stdenv, lib
 , buildPackages
@@ -85,7 +86,7 @@
         version = rustcVersion;
         sha256 = rustcSha256;
         inherit enableRustcDev;
-        inherit llvmShared llvmSharedForBuild llvmSharedForHost llvmSharedForTarget;
+        inherit llvmShared llvmSharedForBuild llvmSharedForHost llvmSharedForTarget llvmPackagesForBuild;
 
         patches = rustcPatches;
 
diff --git a/pkgs/development/compilers/rust/rustc.nix b/pkgs/development/compilers/rust/rustc.nix
index dae944092409..187127cfbfb3 100644
--- a/pkgs/development/compilers/rust/rustc.nix
+++ b/pkgs/development/compilers/rust/rustc.nix
@@ -1,5 +1,5 @@
 { lib, stdenv, removeReferencesTo, pkgsBuildBuild, pkgsBuildHost, pkgsBuildTarget
-, llvmShared, llvmSharedForBuild, llvmSharedForHost, llvmSharedForTarget
+, llvmShared, llvmSharedForBuild, llvmSharedForHost, llvmSharedForTarget, llvmPackagesForBuild
 , fetchurl, file, python3
 , darwin, cmake, rust, rustPlatform
 , pkg-config, openssl
@@ -174,7 +174,10 @@ in stdenv.mkDerivation rec {
 
   requiredSystemFeatures = [ "big-parallel" ];
 
-  passthru.llvm = llvmShared;
+  passthru = {
+    llvm = llvmShared;
+    llvmPackages = llvmPackagesForBuild;
+  };
 
   meta = with lib; {
     homepage = "https://www.rust-lang.org/";
diff --git a/pkgs/development/libraries/nss/3.53.nix b/pkgs/development/libraries/nss/3.53.nix
deleted file mode 100644
index 2f18b466f981..000000000000
--- a/pkgs/development/libraries/nss/3.53.nix
+++ /dev/null
@@ -1,180 +0,0 @@
-{ lib
-, stdenv
-, fetchurl
-, nspr
-, perl
-, zlib
-, sqlite
-, darwin
-, fixDarwinDylibNames
-, buildPackages
-, ninja
-, # allow FIPS mode. Note that this makes the output non-reproducible.
-  # https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_Tech_Notes/nss_tech_note6
-  enableFIPS ? false
-}:
-
-let
-  nssPEM = fetchurl {
-    url = "http://dev.gentoo.org/~polynomial-c/mozilla/nss-3.15.4-pem-support-20140109.patch.xz";
-    sha256 = "10ibz6y0hknac15zr6dw4gv9nb5r5z9ym6gq18j3xqx7v7n3vpdw";
-  };
-in
-stdenv.mkDerivation rec {
-  pname = "nss";
-  version = "3.53.1";
-
-  src = fetchurl {
-    url = "mirror://mozilla/security/nss/releases/NSS_${lib.replaceStrings ["."] ["_"] version}_RTM/src/${pname}-${version}.tar.gz";
-    sha256 = "05jk65x3zy6q8lx2djj8ik7kg741n88iy4n3bblw89cv0xkxxk1d";
-  };
-
-  depsBuildBuild = [ buildPackages.stdenv.cc ];
-
-  nativeBuildInputs = [ perl ninja (buildPackages.python3.withPackages (ps: with ps; [ gyp ])) ]
-    ++ lib.optionals stdenv.hostPlatform.isDarwin [ darwin.cctools fixDarwinDylibNames ];
-
-  buildInputs = [ zlib sqlite ];
-
-  propagatedBuildInputs = [ nspr ];
-
-  prePatch = ''
-    # strip the trailing whitespace from the patch line and the renamed CKO_NETSCAPE_ enum to CKO_NSS_
-    xz -d < ${nssPEM} | sed \
-       -e 's/-DIRS = builtins $/-DIRS = . builtins/g' \
-       -e 's/CKO_NETSCAPE_/CKO_NSS_/g' \
-       -e 's/CKT_NETSCAPE_/CKT_NSS_/g' \
-       | patch -p1
-
-    patchShebangs nss
-
-    for f in nss/coreconf/config.gypi nss/build.sh nss/coreconf/config.gypi; do
-      substituteInPlace "$f" --replace "/usr/bin/env" "${buildPackages.coreutils}/bin/env"
-    done
-
-    substituteInPlace nss/coreconf/config.gypi --replace "/usr/bin/grep" "${buildPackages.coreutils}/bin/env grep"
-  '';
-
-  patches = [
-    # Based on http://patch-tracker.debian.org/patch/series/dl/nss/2:3.15.4-1/85_security_load.patch
-    ./85_security_load.patch
-    ./ckpem.patch
-    ./fix-cross-compilation.patch
-  ];
-
-  patchFlags = [ "-p0" ];
-
-  postPatch = lib.optionalString stdenv.hostPlatform.isDarwin ''
-    substituteInPlace nss/coreconf/Darwin.mk --replace '@executable_path/$(notdir $@)' "$out/lib/\$(notdir \$@)"
-    substituteInPlace nss/coreconf/config.gypi --replace "'DYLIB_INSTALL_NAME_BASE': '@executable_path'" "'DYLIB_INSTALL_NAME_BASE': '$out/lib'"
-  '';
-
-  outputs = [ "out" "dev" "tools" ];
-
-  preConfigure = "cd nss";
-
-  buildPhase =
-    let
-      getArch = platform:
-        if platform.isx86_64 then "x64"
-        else if platform.isx86_32 then "ia32"
-        else if platform.isAarch32 then "arm"
-        else if platform.isAarch64 then "arm64"
-        else if platform.isPower && platform.is64bit then
-          (
-            if platform.isLittleEndian then "ppc64le" else "ppc64"
-          )
-        else platform.parsed.cpu.name;
-      # yes, this is correct. nixpkgs uses "host" for the platform the binary will run on whereas nss uses "host" for the platform that the build is running on
-      target = getArch stdenv.hostPlatform;
-      host = getArch stdenv.buildPlatform;
-    in
-    ''
-      runHook preBuild
-
-      sed -i 's|nss_dist_dir="$dist_dir"|nss_dist_dir="'$out'"|;s|nss_dist_obj_dir="$obj_dir"|nss_dist_obj_dir="'$out'"|' build.sh
-      ./build.sh -v --opt \
-        --with-nspr=${nspr.dev}/include:${nspr.out}/lib \
-        --system-sqlite \
-        --enable-legacy-db \
-        --target ${target} \
-        -Dhost_arch=${host} \
-        -Duse_system_zlib=1 \
-        --enable-libpkix \
-        ${lib.optionalString enableFIPS "--enable-fips"} \
-        ${lib.optionalString stdenv.isDarwin "--clang"} \
-        ${lib.optionalString (stdenv.hostPlatform != stdenv.buildPlatform) "--disable-tests"}
-
-      runHook postBuild
-    '';
-
-  NIX_CFLAGS_COMPILE = "-Wno-error -DNIX_NSS_LIBDIR=\"${placeholder "out"}/lib/\"";
-
-  installPhase = ''
-    runHook preInstall
-
-    rm -rf $out/private
-    find $out -name "*.TOC" -delete
-    mv $out/public $out/include
-
-    ln -s lib $out/lib64
-
-    # Upstream issue: https://bugzilla.mozilla.org/show_bug.cgi?id=530672
-    # https://gitweb.gentoo.org/repo/gentoo.git/plain/dev-libs/nss/files/nss-3.32-gentoo-fixups.patch?id=af1acce6c6d2c3adb17689261dfe2c2b6771ab8a
-    NSS_MAJOR_VERSION=`grep "NSS_VMAJOR" lib/nss/nss.h | awk '{print $3}'`
-    NSS_MINOR_VERSION=`grep "NSS_VMINOR" lib/nss/nss.h | awk '{print $3}'`
-    NSS_PATCH_VERSION=`grep "NSS_VPATCH" lib/nss/nss.h | awk '{print $3}'`
-    PREFIX="$out"
-
-    mkdir -p $out/lib/pkgconfig
-    sed -e "s,%prefix%,$PREFIX," \
-        -e "s,%exec_prefix%,$PREFIX," \
-        -e "s,%libdir%,$PREFIX/lib64," \
-        -e "s,%includedir%,$dev/include/nss," \
-        -e "s,%NSS_VERSION%,$NSS_MAJOR_VERSION.$NSS_MINOR_VERSION.$NSS_PATCH_VERSION,g" \
-        -e "s,%NSPR_VERSION%,4.16,g" \
-        pkg/pkg-config/nss.pc.in > $out/lib/pkgconfig/nss.pc
-    chmod 0644 $out/lib/pkgconfig/nss.pc
-
-    sed -e "s,@prefix@,$PREFIX," \
-        -e "s,@MOD_MAJOR_VERSION@,$NSS_MAJOR_VERSION," \
-        -e "s,@MOD_MINOR_VERSION@,$NSS_MINOR_VERSION," \
-        -e "s,@MOD_PATCH_VERSION@,$NSS_PATCH_VERSION," \
-        pkg/pkg-config/nss-config.in > $out/bin/nss-config
-    chmod 0755 $out/bin/nss-config
-  '';
-
-  postFixup =
-    let
-      isCross = stdenv.hostPlatform != stdenv.buildPlatform;
-      nss = if isCross then buildPackages.nss.tools else "$out";
-    in
-    (lib.optionalString enableFIPS (''
-      for libname in freebl3 nssdbm3 softokn3
-      do libfile="$out/lib/lib$libname${stdenv.hostPlatform.extensions.sharedLibrary}"'' +
-    (if stdenv.isDarwin
-    then ''
-      DYLD_LIBRARY_PATH=$out/lib:${nspr.out}/lib \
-    '' else ''
-      LD_LIBRARY_PATH=$out/lib:${nspr.out}/lib \
-    '') + ''
-          ${nss}/bin/shlibsign -v -i "$libfile"
-      done
-    '')) +
-    ''
-      moveToOutput bin "$tools"
-      moveToOutput bin/nss-config "$dev"
-      moveToOutput lib/libcrmf.a "$dev" # needed by firefox, for example
-      rm -f "$out"/lib/*.a
-
-      runHook postInstall
-    '';
-
-  meta = with lib; {
-    homepage = "https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS";
-    description = "A set of libraries for development of security-enabled client and server applications";
-    maintainers = with maintainers; [ ];
-    license = licenses.mpl20;
-    platforms = platforms.all;
-  };
-}
diff --git a/pkgs/development/libraries/xmlsec/default.nix b/pkgs/development/libraries/xmlsec/default.nix
index 2dceaeda6490..b86189306b8a 100644
--- a/pkgs/development/libraries/xmlsec/default.nix
+++ b/pkgs/development/libraries/xmlsec/default.nix
@@ -1,7 +1,5 @@
 { stdenv, fetchurl, libxml2, gnutls, libxslt, pkg-config, libgcrypt, libtool
-# nss_3_53 is used instead of the latest due to a number of issues:
-# https://github.com/lsh123/xmlsec/issues?q=is%3Aissue+is%3Aopen+nss
-, openssl, nss_3_53, lib, runCommandCC, writeText }:
+, openssl, nss, lib, runCommandCC, writeText }:
 
 lib.fix (self:
 stdenv.mkDerivation rec {
@@ -24,11 +22,11 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ pkg-config ];
 
-  buildInputs = [ libxml2 gnutls libxslt libgcrypt libtool openssl nss_3_53 ];
+  buildInputs = [ libxml2 gnutls libxslt libgcrypt libtool openssl nss ];
 
   enableParallelBuilding = true;
   doCheck = true;
-  checkInputs = [ nss_3_53.tools ];
+  checkInputs = [ nss.tools ];
   preCheck = ''
   substituteInPlace tests/testrun.sh \
     --replace 'timestamp=`date +%Y%m%d_%H%M%S`' 'timestamp=19700101_000000' \
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index a6bf5a42bc2b..b1d5a91b1455 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -12682,16 +12682,6 @@ with pkgs;
     inherit (darwin) apple_sdk;
   };
 
-  # Because rustc-1.46.0 enables static PIE by default for
-  # `x86_64-unknown-linux-musl` this release will suffer from:
-  #
-  # https://github.com/NixOS/nixpkgs/issues/94228
-  #
-  # So this commit doesn't remove the 1.45.2 release.
-  rust_1_45 = callPackage ../development/compilers/rust/1_45.nix {
-    inherit (darwin.apple_sdk.frameworks) CoreFoundation Security SystemConfiguration;
-    llvm_10 = llvmPackages_10.libllvm;
-  };
   rust_1_55 = callPackage ../development/compilers/rust/1_55.nix {
     inherit (darwin.apple_sdk.frameworks) CoreFoundation Security SystemConfiguration;
     llvm_12 = llvmPackages_12.libllvm;
@@ -12702,7 +12692,6 @@ with pkgs;
   mrustc-minicargo = callPackage ../development/compilers/mrustc/minicargo.nix { };
   mrustc-bootstrap = callPackage ../development/compilers/mrustc/bootstrap.nix { };
 
-  rustPackages_1_45 = rust_1_45.packages.stable;
   rustPackages_1_55 = rust_1_55.packages.stable;
   rustPackages = rustPackages_1_55;
 
@@ -18670,9 +18659,6 @@ with pkgs;
   nss = lowPrio (callPackage ../development/libraries/nss { });
   nssTools = nss.tools;
 
-  # required for stable thunderbird and firefox-esr-78
-  nss_3_53 = lowPrio (callPackage ../development/libraries/nss/3.53.nix { });
-
   nss_wrapper = callPackage ../development/libraries/nss_wrapper { };
 
   nsss = skawarePackages.nsss;
@@ -25015,15 +25001,13 @@ with pkgs;
   });
 
   firefox-unwrapped = firefoxPackages.firefox;
-  firefox-esr-78-unwrapped = firefoxPackages.firefox-esr-78;
   firefox-esr-91-unwrapped = firefoxPackages.firefox-esr-91;
   firefox = wrapFirefox firefox-unwrapped { };
   firefox-wayland = wrapFirefox firefox-unwrapped { forceWayland = true; };
-  firefox-esr-78 = wrapFirefox firefox-esr-78-unwrapped { };
   firefox-esr-91 = wrapFirefox firefox-esr-91-unwrapped { };
 
-  firefox-esr = firefox-esr-78;
-  firefox-esr-unwrapped = firefoxPackages.firefox-esr-78;
+  firefox-esr = firefox-esr-91;
+  firefox-esr-unwrapped = firefoxPackages.firefox-esr-91;
   firefox-esr-wayland = wrapFirefox firefox-esr-91-unwrapped { forceWayland = true; };
 
   firefox-bin-unwrapped = callPackage ../applications/networking/browsers/firefox-bin {
@@ -28300,9 +28284,7 @@ with pkgs;
   });
 
   thunderbird-unwrapped = thunderbirdPackages.thunderbird;
-  thunderbird-78-unwrapped = thunderbirdPackages.thunderbird-78;
   thunderbird = wrapThunderbird thunderbird-unwrapped { };
-  thunderbird-78 = wrapThunderbird thunderbird-78-unwrapped { };
   thunderbird-wayland = wrapThunderbird thunderbird-unwrapped { forceWayland = true; };
 
   thunderbolt = callPackage ../os-specific/linux/thunderbolt {};