diff --git a/rbm.conf b/rbm.conf
index c4f73e5..e3878b5 100644
--- a/rbm.conf
+++ b/rbm.conf
@@ -24,7 +24,13 @@ buildconf:
   git_signtag_opt: '-s'
 
 var:
+  ncdns_version: '10.5a5'
+  ncdns_build: 'build2'
+  ncdns_incremental_from:
+    - 10.5a3
   project_name: tor-browser
+  multi_lingual: 0
+  build_mar: 1
   # By default, we sort the list of installed packages. This allows sharing
   # containers with identical list of packages, even if they are not listed
   # in the same order. In the cases where the installation order is
@@ -40,7 +46,8 @@ var:
     [% END -%]
     input_files: [% c("input_files_id") %]
     build:
-    [% c("build", { filename => 'f', output_dir => '/out', norec => {} }) %]
+    [% SET step = c("step") -%]
+    [% c(step, { filename => 'f', output_dir => '/out', norec => {} }) %]
   container:
     dir: '[% c("rbm_tmp_dir") %]/rbm-containers/[% sha256(c("build_id")) %]'
     user: rbm
@@ -55,6 +62,76 @@ var:
   faketime: "faketime -f \"[% USE date; GET date.format(c('timestamp'), format = '%Y-%m-%d %H:%M:%S') %]\""
   touch: "[% USE date %]touch -m -t [% date.format(c('timestamp'), format = '%Y%m%d%H%M') %]"
 
+  locale_ja: ja
+  locales:
+    - ar
+    - ca
+    - cs
+    - da
+    - de
+    - el
+    - es-AR
+    - es-ES
+    - fa
+    - fr
+    - ga-IE
+    - he
+    - hu
+    - id
+    - is
+    - it
+    - '[% c("var/locale_ja") %]'
+    - ka
+    - ko
+    - lt
+    - mk
+    - ms
+    - nb-NO
+    - nl
+    - pl
+    - pt-BR
+    - ro
+    - ru
+    - sv-SE
+    - th
+    - tr
+    - vi
+    - zh-CN
+    - zh-TW
+  locales_mobile:
+    - ar
+    - ca
+    - cs
+    - da
+    - de
+    - el
+    - es-rAR
+    - es-rES
+    - fa
+    - fr
+    - ga-rIE
+    - hu
+    - in
+    - is
+    - it
+    - iw
+    - ja
+    - ka
+    - ko
+    - lt
+    - nb-rNO
+    - nl
+    - pl
+    - pt-rBR
+    - ro
+    - ru
+    - sv-rSE
+    - th
+    - tr
+    - vi
+    - zh-rCN
+    - zh-rTW
+
   sign_build: '[% ENV.RBM_SIGN_BUILD %]'
   sign_build_gpg_opts: '[% ENV.RBM_GPG_OPTS %]'
 
@@ -84,6 +161,11 @@ var:
       rm -Rf /var/tmp/build /var/tmp/dist
     [% END -%]
 
+  DOCSDIR_project: '[% project %]'
+  set_PTDIR_DOCSDIR: |
+    PTDIR="$distdir/TorBrowser/Tor/PluggableTransports"
+    DOCSDIR="$distdir/TorBrowser/Docs/[% c("var/DOCSDIR_project") %]"
+
 targets:
   notarget: linux-x86_64
   noint:
@@ -93,14 +175,50 @@ targets:
     var:
       release: 1
       channel: release
+  alpha:
+    var:
+      alpha: 1
+      channel: alpha
+  nightly:
+    fetch: 1
+    var:
+      nightly: 1
+      channel: nightly
+      ncdns_version: |
+        [%
+           IF ENV.TORBROWSER_NIGHTLY_VERSION;
+                GET ENV.TORBROWSER_NIGHTLY_VERSION;
+           ELSIF c("var/testbuild");
+                GET "testbuild";
+           ELSE;
+                GET c("var_p/nightly_ncdns_version");
+           END;
+        -%]
+      # For nightly builds, we support updates for a limited set of locales
+      mar_locales:
+        - de
+        - es-ES
+        - fr
+        - ru
+      max_ncdns_incremental_from: 2
+      build_infos_json: 1
 
-  # The common-stretch target is used to build components that are common to all
-  # platforms, using Debian stretch.
-  common-stretch:
+  ncdns-testbuild:
+    - testbuild
+    - alpha
+  testbuild:
+    var:
+      testbuild: 1
+      # Don't create mar files to save time
+      build_mar: 0
+
+  # The common-buster target is used to build components that are common to all
+  # platforms, using Debian Buster.
+  common-buster:
     var:
       common: 1
       container:
-        suite: stretch
+        suite: buster
         arch: amd64
       pre_pkginst: ''
       deps:
@@ -120,6 +238,8 @@ targets:
       android-armv7: 1
       osname: android-armv7
       toolchain_arch: arm
+      abi: armeabi-v7a
+      cross_prefix: armv7a-linux-androideabi
   ncdns-android-x86:
     - android-x86
     - android
@@ -129,6 +249,8 @@ targets:
       android-x86: 1
       osname: android-x86
       toolchain_arch: x86
+      abi: x86
+      cross_prefix: i686-linux-android
   ncdns-android-x86_64:
     - android-x86_64
     - android
@@ -138,6 +260,8 @@ targets:
       android-x86_64: 1
       osname: android-x86_64
       toolchain_arch: x86_64
+      abi: x86_64
+      cross_prefix: x86_64-linux-android
   ncdns-android-aarch64:
     - android-aarch64
     - android
@@ -147,22 +271,32 @@ targets:
       android-aarch64: 1
       osname: android-aarch64
       toolchain_arch: arm64
+      abi: arm64-v8a
+      cross_prefix: aarch64-linux-android
   android:
     var:
       android: 1
       compiler: android-toolchain
-      # API 16 is the minimum we currently support for Tor Browser on Android
       android_min_api: '[% GET c("var/android_min_api_" _ c("arch")) %]'
-      # API 21 is the minimum we currently support for arm64 on Android
-      android_min_api_aarch64: 21
+      CC: '[% c("var/cross_prefix") %][% c("var/android_min_api") %]-clang'
+      CXX: '[% c("var/cross_prefix") %][% c("var/android_min_api") %]-clang'
+      # API 16 is the minimum we currently support for 32 bit on Android
       android_min_api_armv7: 16
       android_min_api_x86: 16
+      # API 21 is the minimum we currently support for 64 bit on Android
       android_min_api_x86_64: 21
-      CC: '$ANDROID_NDK_HOME/[% c("var/toolchain_arch") %]/bin/clang'
-      CXX: '$ANDROID_NDK_HOME/[% c("var/toolchain_arch") %]/bin/clang++'
+      android_min_api_aarch64: 21
+      # This is needed to get the offline build part for Glean right.
+      glean_parser: 1.28.6
+      # We only build snowflake on the alpha and nightly
+      # channels for now.
+      snowflake: '[% c("var/alpha") || c("var/nightly") %]'
       container:
-        suite: stretch
+        suite: buster
         arch: amd64
+        disable_network:
+          # Disable network in the script for merging GeckoView .aar files
+          merge_aars: 1
       deps:
         - build-essential
         - python
@@ -170,10 +304,26 @@ targets:
         - libtool
         - zip
         - unzip
+        - libtinfo5
+      configure_opt: '--host=[% c("var/cross_prefix") %] CC=[% c("var/CC") %] [% c("var/configure_opt_project") %]'
 
+      pre_pkginst: |
+          SNAPSHOT_VERSION=20191201T212855Z
+          OPENJDK_URL=https://snapshot.debian.org/archive/debian/$SNAPSHOT_VERSION/pool/main/o/openjdk-8
+          JDK_VERSION=8u232-b09-1~deb9u1_amd64
+          apt-get install -y -q wget ca-certificates-java
+          wget $OPENJDK_URL/openjdk-8-jdk-headless_$JDK_VERSION.deb
+          wget $OPENJDK_URL/openjdk-8-jre-headless_$JDK_VERSION.deb
+          echo 92b4f8fb77d793a86e0b03b3b0750592b40a26a5d75956d10dd984a7b3aad4c9 openjdk-8-jdk-headless_$JDK_VERSION.deb | sha256sum -c
+          echo 84bf52b6cce20ead08b0d5b9fd9b81b4aa3da385ca951b313fe11d5cb1aa4d17 openjdk-8-jre-headless_$JDK_VERSION.deb | sha256sum -c
+          dpkg -i ./openjdk-8-jre-headless_$JDK_VERSION.deb ./openjdk-8-jdk-headless_$JDK_VERSION.deb
   ncdns-linux-x86_64:
     - linux-x86_64
     - linux
+  ncdns-linux-x86_64-asan:
+    - linux-asan
+    - linux-x86_64
+    - linux
   ncdns-linux-i686:
     - linux-i686
     - linux
@@ -182,19 +332,26 @@ targets:
     var:
       linux-x86_64: 1
       osname: linux-x86_64
+      # We only support RLBox on the nightly channel and x86_64 for now
+      rlbox: '[% c("var/nightly") %]'
   linux-i686:
     arch: i686
     var:
       linux-i686: 1
       osname: linux-i686
-      configure_opt_i686: '--host=i686-linux-gnu CFLAGS=-m32 CXXFLAGS=-m32 LDFLAGS=-m32'
-      configure_opt: '[% c("var/configure_opt_i686") %]'
+      configure_opt: '--host=i686-linux-gnu CFLAGS=-m32 CXXFLAGS=-m32 LDFLAGS=-m32 [% c("var/configure_opt_project") %]'
   linux:
     var:
       linux: 1
       compiler: gcc
+      configure_opt: '[% c("var/configure_opt_project") %]'
+      # We only build snowflake on the alpha and nightly
+      # channels for now.
+      snowflake: '[% c("var/alpha") || c("var/nightly") %]'
+      # Only build Namecoin for linux on nightly
+      namecoin: '[% c("var/nightly") %]'
       container:
-        suite: wheezy
+        suite: jessie
         arch: amd64
       pre_pkginst: dpkg --add-architecture i386
       deps:
@@ -208,6 +365,13 @@ targets:
         - libtool
         - zip
         - unzip
+  linux-asan:
+    var:
+      asan: 1
+      # RLBox needs clang to create .wasm files but we use mostly GCC for our
+      # ASan builds. Thus, the compilation currently breaks with RLBox enabled.
+      # See: tor-browser-build#40063.
+      rlbox: 0
 
   ncdns-windows-i686:
     - windows-i686
@@ -219,6 +383,7 @@ targets:
     arch: x86_64
     var:
       windows-x86_64: 1
+      windows-i686: 0
       osname: windows-x86_64
       # HEASLR is 64 bit only (see bug 12968)
       flag_HEASLR: '-Wl,--high-entropy-va'
@@ -226,19 +391,25 @@ targets:
     arch: i686
     var:
       windows-i686: 1
+      windows-x86_64: 0
       osname: windows-i686
+      # mingw-w64 does not support SEH on 32bit systems. Be explicit about that.
+      flag_noSEH: '-Wl,--no-seh'
   windows:
     var:
       windows: 1
       container:
-        suite: stretch
+        suite: buster
         arch: amd64
-      configure_opt: '--host=[% c("arch") %]-w64-mingw32 CFLAGS="[% c("var/CFLAGS") %]" LDFLAGS="[% c("var/LDFLAGS") %]"'
+      configure_opt: '--host=[% c("arch") %]-w64-mingw32 CFLAGS="[% c("var/CFLAGS") %]" LDFLAGS="[% c("var/LDFLAGS") %]" [% c("var/configure_opt_project") %]'
       CFLAGS: '-fstack-protector-strong -fno-strict-overflow -Wno-missing-field-initializers -Wformat -Wformat-security [% c("var/flag_mwindows") %]'
-      LDFLAGS: '-Wl,--dynamicbase -Wl,--nxcompat -Wl,--enable-reloc-section -Wl,--no-insert-timestamp -lssp -L$gcclibs [% c("var/flag_HEASLR") %] [% c("var/flag_mwindows") %]'
+      LDFLAGS: '-Wl,--dynamicbase -Wl,--nxcompat -Wl,--enable-reloc-section -Wl,--no-insert-timestamp -lssp -L$gcclibs [% c("var/flag_HEASLR") %] [% c("var/flag_noSEH") %] [% c("var/flag_mwindows") %]'
       flag_mwindows: '-mwindows'
       compiler: mingw-w64
       faketime_path: /usr/lib/x86_64-linux-gnu/faketime/libfaketime.so.1
+      # We only build snowflake on the alpha and nightly
+      # channels for now.
+      snowflake: '[% c("var/alpha") || c("var/nightly") %]'
       deps:
         - build-essential
         - python
@@ -256,13 +427,19 @@ targets:
       osx: 1
       osname: osx-x86_64
       container:
-        suite: stretch
+        suite: buster
         arch: amd64
       compiler: 'macosx-toolchain'
-      configure_opt: '--host=x86_64-apple-darwin11 CC="x86_64-apple-darwin11-clang [% c("var/FLAGS") %]" CXX="x86_64-apple-darwin11-clang++ [% c("var/FLAGS") %]"'
-      FLAGS: "-target x86_64-apple-darwin11 -B $cctoolsdir -isysroot $sysrootdir"
+      configure_opt: '--host=x86_64-apple-darwin CC="x86_64-apple-darwin-clang [% c("var/FLAGS") %]" CXX="x86_64-apple-darwin-clang++ [% c("var/FLAGS") %]" [% c("var/configure_opt_project") %]'
+      FLAGS: "-target x86_64-apple-darwin -B $cctoolsdir -isysroot $sysrootdir"
       LDFLAGS: "-Wl,-syslibroot,$sysrootdir -Wl,-dead_strip -Wl,-pie"
       macosx_deployment_target: '10.9'
+      locale_ja: ja-JP-mac
+      # We only support RLBox on the nightly channel for now
+      rlbox: '[% c("var/nightly") %]'
+      # We only build snowflake on the alpha and nightly
+      # channels for now.
+      snowflake: '[% c("var/alpha") || c("var/nightly") %]'
       deps:
         - build-essential
         - python
@@ -271,6 +448,9 @@ targets:
         - zip
         - unzip
       faketime_path: /usr/lib/x86_64-linux-gnu/faketime/libfaketime.so.1
+      set_PTDIR_DOCSDIR: |
+        PTDIR="$distdir/Contents/MacOS/Tor/PluggableTransports"
+        DOCSDIR="$distdir/Contents/Resources/TorBrowser/Docs/[% c("var/DOCSDIR_project") %]"
 
   # The no_build_id target can be useful if you want to quickly display
   # a build template or other option but don't want to spend time to
@@ -423,5 +603,30 @@ ENV:
         my ($out) = capture_exec('sudo', 'runc', '--version');
         return $out =~ m/^.*spec: 1\.[0-9]+\.[0-9]+(?:-dev)?$/m;
       },
+      nightly_ncdns_version => sub {
+        state $version = '';
+        return $version if $version;
+        my (undef, undef, undef, $day, $mon, $year) = gmtime;
+        $version = sprintf("tbb-nightly.%u.%02u.%02u", $year + 1900, $mon + 1, $day);
+        return $version;
+      },
+      nightly_ncdns_incremental_from => sub {
+        my ($project, $options) = @_;
+        my $nightly_dir = project_config($project, 'basedir', $options) . '/nightly';
+        my $current_version = project_config($project, 'var/ncdns_version', $options);
+        use Path::Tiny;
+        return [] unless -d $nightly_dir;
+        my @dirs = sort map { $_->basename } path($nightly_dir)->children(qr/^tbb-nightly\./);
+        my $nb_incr = project_config($project, ['var', 'max_ncdns_incremental_from'], $options);
+        my @res;
+        while ($nb_incr > 0) {
+          my $dir = pop @dirs;
+          last unless $dir;
+          next if $dir eq $current_version;
+          $nb_incr--;
+          push @res, $dir;
+        }
+        return [@res];
+      },
     },
   )
diff --git a/tools/patch-tor-to-namecoin.sh b/tools/patch-tor-to-namecoin.sh
new file mode 100755
index 0000000..7035fe4
--- /dev/null
+++ b/tools/patch-tor-to-namecoin.sh
@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+set -euxo pipefail
+shopt -s nullglob globstar
+
+cat tor-browser-build/rbm.conf | sed "s/torbrowser/ncdns/g" > rbm.conf