diff --git a/build/macosx/universal/flight.mk b/build/macosx/universal/flight.mk
new file mode 100644
index 00000000000..00e2396fe03
--- /dev/null
+++ b/build/macosx/universal/flight.mk
@@ -0,0 +1,105 @@
+# ***** BEGIN LICENSE BLOCK *****
+# Version: MPL 1.1/GPL 2.0/LGPL 2.1
+#
+# The contents of this file are subject to the Mozilla Public License Version
+# 1.1 (the "License"); you may not use this file except in compliance with
+# the License. You may obtain a copy of the License at
+# http://www.mozilla.org/MPL/
+#
+# Software distributed under the License is distributed on an "AS IS" basis,
+# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+# for the specific language governing rights and limitations under the
+# License.
+#
+# The Original Code is the Mozilla Mac OS X Universal Binary Packaging System
+#
+# The Initial Developer of the Original Code is Google Inc.
+# Portions created by the Initial Developer are Copyright (C) 2006
+# the Initial Developer. All Rights Reserved.
+#
+# Contributor(s):
+#  Mark Mentovai <mark@moxienet.com> (Original Author)
+#
+# Alternatively, the contents of this file may be used under the terms of
+# either the GNU General Public License Version 2 or later (the "GPL"), or
+# the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+# in which case the provisions of the GPL or the LGPL are applicable instead
+# of those above. If you wish to allow use of your version of this file only
+# under the terms of either the GPL or the LGPL, and not to allow others to
+# use your version of this file under the terms of the MPL, indicate your
+# decision by deleting the provisions above and replace them with the notice
+# and other provisions required by the GPL or the LGPL. If you do not delete
+# the provisions above, a recipient may use your version of this file under
+# the terms of any one of the MPL, the GPL or the LGPL.
+#
+# ***** END LICENSE BLOCK *****
+
+# BE CAREFUL!  This makefile handles a postflight_all rule for a
+# multi-project build, so DON'T rely on anything that might differ between
+# the two OBJDIRs.
+
+ifndef OBJDIR
+OBJDIR_PPC = $(MOZ_OBJDIR)/ppc
+OBJDIR_X86 = $(MOZ_OBJDIR)/i386
+DIST_PPC = $(OBJDIR_PPC)/dist
+DIST_X86 = $(OBJDIR_X86)/dist
+DIST_UNI = $(DIST_PPC)/universal
+OBJDIR = $(OBJDIR_PPC)
+endif
+
+include $(OBJDIR)/config/autoconf.mk
+
+DIST = $(OBJDIR)/dist
+
+ifeq ($(MOZ_BUILD_APP),macbrowser)
+INSTALLER_DIR = camino/installer
+MOZ_PKG_APPNAME = camino
+APPNAME_BASE = Camino
+BUILDCONFIG_JAR = Contents/MacOS/chrome/embed.jar
+else
+ifeq ($(MOZ_BUILD_APP),suite)
+INSTALLER_DIR = xpinstall/packager
+else
+INSTALLER_DIR = $(MOZ_BUILD_APP)/installer
+endif
+MOZ_PKG_APPNAME = $(MOZ_APP_NAME)
+APPNAME_BASE = $(MOZ_APP_DISPLAYNAME)
+BUILDCONFIG_JAR = Contents/MacOS/chrome/toolkit.jar
+endif
+
+ifdef MOZ_DEBUG
+APPNAME = $(APPNAME_BASE)Debug
+else
+APPNAME = $(APPNAME_BASE)
+endif
+
+postflight_all:
+# Build the universal package out of only the bits that would be released.
+# Call the packager to set this up.  Set UNIVERSAL_BINARY= to avoid producing
+# a universal binary too early, before the unified bits have been staged.
+# Set MAKE_PACKAGE= to avoid building a dmg.  Set SIGN_NSS= to skip shlibsign.
+	$(MAKE) -C $(OBJDIR_PPC)/$(INSTALLER_DIR) \
+          UNIVERSAL_BINARY= MAKE_PACKAGE= SIGN_NSS=
+	$(MAKE) -C $(OBJDIR_X86)/$(INSTALLER_DIR) \
+          UNIVERSAL_BINARY= MAKE_PACKAGE= SIGN_NSS=
+# Remove .chk files that may have been copied from the NSS build.  These will
+# cause unify to warn or fail if present.  New .chk files that are
+# appropriate for the merged libraries will be generated when the universal
+# dmg is built.
+	rm -f $(DIST_PPC)/$(MOZ_PKG_APPNAME)/$(APPNAME).app/Contents/MacOS/*.chk \
+	      $(DIST_X86)/$(MOZ_PKG_APPNAME)/$(APPNAME).app/Contents/MacOS/*.chk
+# The only difference betewen the two trees now should be the
+# about:buildconfig page.  Fix it up.
+	$(TOPSRCDIR)/build/macosx/universal/fix-buildconfig \
+	  $(DIST_PPC)/$(MOZ_PKG_APPNAME)/$(APPNAME).app/$(BUILDCONFIG_JAR) \
+	  $(DIST_X86)/$(MOZ_PKG_APPNAME)/$(APPNAME).app/$(BUILDCONFIG_JAR)
+	mkdir -p $(DIST_UNI)/$(MOZ_PKG_APPNAME)
+	rm -f $(DIST_X86)/universal
+	ln -s $(DIST_UNI) $(DIST_X86)/universal
+	rm -rf $(DIST_UNI)/$(MOZ_PKG_APPNAME)/$(APPNAME).app
+	$(TOPSRCDIR)/build/macosx/universal/unify \
+	  $(DIST_PPC)/$(MOZ_PKG_APPNAME)/$(APPNAME).app \
+	  $(DIST_X86)/$(MOZ_PKG_APPNAME)/$(APPNAME).app \
+	  $(DIST_UNI)/$(MOZ_PKG_APPNAME)/$(APPNAME).app
+# A universal .dmg can now be produced by making in either architecture's
+# INSTALLER_DIR.
diff --git a/build/macosx/universal/mozconfig b/build/macosx/universal/mozconfig
new file mode 100644
index 00000000000..04ef7091cb9
--- /dev/null
+++ b/build/macosx/universal/mozconfig
@@ -0,0 +1,102 @@
+# ***** BEGIN LICENSE BLOCK *****
+# Version: MPL 1.1/GPL 2.0/LGPL 2.1
+#
+# The contents of this file are subject to the Mozilla Public License Version
+# 1.1 (the "License"); you may not use this file except in compliance with
+# the License. You may obtain a copy of the License at
+# http://www.mozilla.org/MPL/
+#
+# Software distributed under the License is distributed on an "AS IS" basis,
+# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+# for the specific language governing rights and limitations under the
+# License.
+#
+# The Original Code is the Mozilla Mac OS X Universal Binary Packaging System
+#
+# The Initial Developer of the Original Code is Google Inc.
+# Portions created by the Initial Developer are Copyright (C) 2006
+# the Initial Developer. All Rights Reserved.
+#
+# Contributor(s):
+#  Mark Mentovai <mark@moxienet.com> (Original Author)
+#
+# Alternatively, the contents of this file may be used under the terms of
+# either the GNU General Public License Version 2 or later (the "GPL"), or
+# the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+# in which case the provisions of the GPL or the LGPL are applicable instead
+# of those above. If you wish to allow use of your version of this file only
+# under the terms of either the GPL or the LGPL, and not to allow others to
+# use your version of this file under the terms of the MPL, indicate your
+# decision by deleting the provisions above and replace them with the notice
+# and other provisions required by the GPL or the LGPL. If you do not delete
+# the provisions above, a recipient may use your version of this file under
+# the terms of any one of the MPL, the GPL or the LGPL.
+#
+# ***** END LICENSE BLOCK *****
+
+# As used here, arguments in $MOZ_BUILD_PROJECTS are suitable as arguments
+# to gcc's -arch parameter.
+mk_add_options MOZ_BUILD_PROJECTS="ppc i386"
+
+mk_add_options MOZ_UNIFY_BDATE=1
+
+mk_add_options MOZ_POSTFLIGHT_ALL+=build/macosx/universal/flight.mk
+
+DARWIN_VERSION=`uname -r`
+ac_add_app_options ppc  --target=powerpc-apple-darwin$DARWIN_VERSION
+ac_add_app_options i386 --target=i386-apple-darwin$DARWIN_VERSION
+
+# ppc builds run on older systems.  The minimum SDK for x86 is 10.4u.
+ac_add_app_options ppc  --with-macos-sdk=/Developer/SDKs/MacOSX10.2.8.sdk
+ac_add_app_options i386 --with-macos-sdk=/Developer/SDKs/MacOSX10.4u.sdk
+
+# $MOZ_BUILD_APP is only defined when sourced by configure.  That's not a
+# problem, because the variables it affects only need to be set for
+# configure.
+if test -n "$MOZ_BUILD_APP" ; then
+  TARGET_CPU=$MOZ_BUILD_APP
+
+  # When compiling C++, Apple gcc 4.0 produces output that requires a minimum
+  # of 10.3.9.  Use 4.0 for the x86 build, which has a higher minimum than
+  # that.  Use 3.3 for ppc, which must run on older systems.  This will
+  # completely override the compiler selected with the gcc_select command.
+  if test "$TARGET_CPU" = "ppc" ; then
+    GCC_VERSION=3.3
+  else
+    GCC_VERSION=4.0
+  fi
+
+  # It's not strictly necessary to specify -arch during native builds, but it
+  # makes the merged about:buildconfig easier to follow, and it reduces
+  # conditionalized differences between builds.
+  CC="gcc-$GCC_VERSION -arch $TARGET_CPU"
+  CXX="g++-$GCC_VERSION -arch $TARGET_CPU"
+
+  # $HOST_CXX is presently unused.  $HOST_CC will only be used during a cross
+  # compile.  Always use the 4.0 compiler, since it will always be present and
+  # will always work.
+  HOST_CC=gcc-4.0
+  HOST_CXX=g++-4.0
+
+  # These must be set for cross builds, and don't hurt straight builds.
+  RANLIB=ranlib
+  AR=ar
+  AS=$CC
+  LD=ld
+  STRIP="strip -x -S"
+
+  NATIVE_CPU=`uname -p`
+  if test "$NATIVE_CPU" = "powerpc" ; then
+    NATIVE_CPU=ppc
+  fi
+
+  # Let configure know that we mean business.
+  if test "$NATIVE_CPU" != "$TARGET_CPU" ; then
+    CROSS_COMPILE=1
+  fi
+
+  # Each per-CPU build should be entirely oblivious to the fact that a
+  # universal binary will be produced.  The exception is packager.mk, which
+  # needs to know to look for universal bits when building the .dmg.
+  UNIVERSAL_BINARY=1
+fi
diff --git a/config/autoconf.mk.in b/config/autoconf.mk.in
index 2e8267372a9..d6582adc566 100644
--- a/config/autoconf.mk.in
+++ b/config/autoconf.mk.in
@@ -591,6 +591,7 @@ NEXT_ROOT	= @NEXT_ROOT@
 GCC_VERSION	= @GCC_VERSION@
 XCODEBUILD_VERSION= @XCODEBUILD_VERSION@
 HAS_XCODE_2_1	= @HAS_XCODE_2_1@
+UNIVERSAL_BINARY= @UNIVERSAL_BINARY@
 
 VISIBILITY_FLAGS = @VISIBILITY_FLAGS@
 WRAP_SYSTEM_INCLUDES = @WRAP_SYSTEM_INCLUDES@
diff --git a/configure.in b/configure.in
index 9a149ddc52a..2af9e8bcbce 100644
--- a/configure.in
+++ b/configure.in
@@ -643,6 +643,10 @@ AC_SUBST(GCC_VERSION)
 AC_SUBST(XCODEBUILD_VERSION)
 AC_SUBST(HAS_XCODE_2_1)
 
+dnl The universal machinery sets UNIVERSAL_BINARY to inform packager.mk
+dnl that a universal binary is being produced.
+AC_SUBST(UNIVERSAL_BINARY)
+
 dnl ========================================================
 dnl = Mac OS X SDK support
 dnl ========================================================
diff --git a/toolkit/mozapps/installer/packager.mk b/toolkit/mozapps/installer/packager.mk
index 5a5b5e8abc2..ba685d1db84 100644
--- a/toolkit/mozapps/installer/packager.mk
+++ b/toolkit/mozapps/installer/packager.mk
@@ -124,8 +124,11 @@ ifneq (,$(MOZ_PKG_MAC_EXTRA))
 PKG_DMG_FLAGS += $(MOZ_PKG_MAC_EXTRA)
 endif
 _ABS_TOPSRCDIR = $(shell cd $(topsrcdir) && pwd)
+ifdef UNIVERSAL_BINARY
+STAGEPATH = universal/
+endif
 MAKE_PACKAGE	= $(_ABS_TOPSRCDIR)/build/package/mac_osx/pkg-dmg \
-  --source "$(MOZ_PKG_APPNAME)" --target "$(PACKAGE)" \
+  --source "$(STAGEPATH)$(MOZ_PKG_APPNAME)" --target "$(PACKAGE)" \
   --volname "$(MOZ_APP_DISPLAYNAME)" $(PKG_DMG_FLAGS)
 UNMAKE_PACKAGE	= \
   set -ex; \
@@ -160,19 +163,25 @@ endif
 
 # dummy macro if we don't have PSM built
 SIGN_NSS		=
-ifndef CROSS_COMPILE
+ifneq (1_,$(if $(CROSS_COMPILE),1,0)_$(UNIVERSAL_BINARY))
 ifdef MOZ_PSM
 SIGN_NSS		= @echo signing nss libraries;
 
+ifdef UNIVERSAL_BINARY
+NATIVE_ARCH	= $(shell uname -p | sed -e s/powerpc/ppc/)
+NATIVE_DIST	= $(DIST)/../../$(NATIVE_ARCH)/dist
+SIGN_CMD	= $(NATIVE_DIST)/bin/run-mozilla.sh $(NATIVE_DIST)/bin/shlibsign -v -i
+else
 SIGN_CMD	= $(DIST)/bin/run-mozilla.sh $(DEPTH)/nss/shlibsign -v -i
+endif
 
-SOFTOKN		= $(DIST)/$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)softokn3$(DLL_SUFFIX)
-FREEBL		= $(DIST)/$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl3$(DLL_SUFFIX)
-FREEBL_32FPU	= $(DIST)/$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl_32fpu_3$(DLL_SUFFIX)
-FREEBL_32INT	= $(DIST)/$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl_32int_3$(DLL_SUFFIX)
-FREEBL_32INT64	= $(DIST)/$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl_32int64_3$(DLL_SUFFIX)
-FREEBL_64FPU	= $(DIST)/$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl_64fpu_3$(DLL_SUFFIX)
-FREEBL_64INT	= $(DIST)/$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl_64int_3$(DLL_SUFFIX)
+SOFTOKN		= $(DIST)/$(STAGEPATH)$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)softokn3$(DLL_SUFFIX)
+FREEBL		= $(DIST)/$(STAGEPATH)$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl3$(DLL_SUFFIX)
+FREEBL_32FPU	= $(DIST)/$(STAGEPATH)$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl_32fpu_3$(DLL_SUFFIX)
+FREEBL_32INT	= $(DIST)/$(STAGEPATH)$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl_32int_3$(DLL_SUFFIX)
+FREEBL_32INT64	= $(DIST)/$(STAGEPATH)$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl_32int64_3$(DLL_SUFFIX)
+FREEBL_64FPU	= $(DIST)/$(STAGEPATH)$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl_64fpu_3$(DLL_SUFFIX)
+FREEBL_64INT	= $(DIST)/$(STAGEPATH)$(MOZ_PKG_APPNAME)$(_BINPATH)/$(DLL_PREFIX)freebl_64int_3$(DLL_SUFFIX)
 
 SIGN_NSS	+= $(SIGN_CMD) $(SOFTOKN); \
 	if test -f $(FREEBL); then $(SIGN_CMD) $(FREEBL); fi; \
@@ -273,14 +282,18 @@ ifdef MOZ_PKG_MANIFEST
 	$(PERL) $(topsrcdir)/xpinstall/packager/xptlink.pl -s $(DIST) -d $(DIST)/xpt -f $(DIST)/$(MOZ_PKG_APPNAME)/components -v
 else # !MOZ_PKG_MANIFEST
 ifeq ($(MOZ_PKG_FORMAT),DMG)
+# If UNIVERSAL_BINARY, the package will be made from an already-prepared
+# STAGEPATH
+ifndef UNIVERSAL_BINARY
 	@cd $(DIST) && rsync -auv --copy-unsafe-links $(_APPNAME) $(MOZ_PKG_APPNAME)
+endif
 else
 	@cd $(DIST)/bin && tar $(TAR_CREATE_FLAGS) - * | (cd ../$(MOZ_PKG_APPNAME); tar -xf -)
 endif # DMG
 endif # MOZ_PKG_MANIFEST
 ifndef PKG_SKIP_STRIP
 	@echo "Stripping package directory..."
-	@cd $(DIST)/$(MOZ_PKG_APPNAME); find . ! -type d \
+	@cd $(DIST)/$(STAGEPATH)$(MOZ_PKG_APPNAME); find . ! -type d \
 			! -name "*.js" \
 			! -name "*.xpt" \
 			! -name "*.gif" \
@@ -307,10 +320,10 @@ ifndef PKG_SKIP_STRIP
 endif
 	@echo "Removing unpackaged files..."
 ifdef NO_PKG_FILES
-	cd $(DIST)/$(MOZ_PKG_APPNAME)$(_BINPATH); rm -rf $(NO_PKG_FILES)
+	cd $(DIST)/$(STAGEPATH)$(MOZ_PKG_APPNAME)$(_BINPATH); rm -rf $(NO_PKG_FILES)
 endif
 ifdef MOZ_PKG_REMOVALS
-	$(SYSINSTALL) $(MOZ_PKG_REMOVALS_GEN) $(DIST)/$(MOZ_PKG_APPNAME)$(_BINPATH)
+	$(SYSINSTALL) $(MOZ_PKG_REMOVALS_GEN) $(DIST)/$(STAGEPATH)$(MOZ_PKG_APPNAME)$(_BINPATH)
 endif # MOZ_PKG_REMOVALS
 	@echo "Compressing..."
 	cd $(DIST); $(MAKE_PACKAGE)