--- a/im/app/Makefile.in
+++ b/im/app/Makefile.in
@@ -40,20 +40,20 @@ DEPTH		= ../..
 topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
 AB_CD = $(MOZ_UI_LOCALE) 
 
-GRE_MILESTONE = $(shell $(PYTHON) $(topsrcdir)/config/printconfigsetting.py $(LIBXUL_DIST)/bin/platform.ini Build Milestone)
-GRE_BUILDID = $(shell $(PYTHON) $(topsrcdir)/config/printconfigsetting.py $(LIBXUL_DIST)/bin/platform.ini Build BuildID)
+GRE_MILESTONE = $(shell $(PYTHON) $(MOZILLA_SRCDIR)/config/printconfigsetting.py $(LIBXUL_DIST)/bin/platform.ini Build Milestone)
+GRE_BUILDID = $(shell $(PYTHON) $(MOZILLA_SRCDIR)/config/printconfigsetting.py $(LIBXUL_DIST)/bin/platform.ini Build BuildID)
 
-PLATFORM_LICENSE_FILE = $(topsrcdir)/toolkit/content/license.html
+PLATFORM_LICENSE_FILE = $(MOZILLA_SRCDIR)/toolkit/content/license.html
 MAIL_LICENSE_HTML_FILE = ../license.html
 MAIL_LICENSE_TXT_FILE = $(topsrcdir)/instantbird/LICENSE.txt
 MAIL_APP_LICENSE_FILE = $(srcdir)/app-license.html
 
 DEFINES += \
   -DINSTANTBIRD_ICO=\"$(DIST)/branding/instantbird.ico\" \
   -DAB_CD=$(AB_CD) \
   -DGRE_MILESTONE=$(GRE_MILESTONE) \
@@ -84,17 +84,17 @@ REQUIRES = \
 	string \
 	xulapp \
 	$(NULL)
 
 CPPSRCS = nsMain.cpp
 
 DIST_FILES = application.ini
 
-LOCAL_INCLUDES += -I$(topsrcdir)/toolkit/xre
+LOCAL_INCLUDES += -I$(MOZILLA_SRCDIR)/toolkit/xre
 
 ifeq (,$(filter mac cocoa,$(MOZ_WIDGET_TOOLKIT)))
 EXTRA_COMPONENTS = profileMigrator.js
 endif
 
 ifdef BUILD_STATIC_LIBS
 ifdef _MSC_VER
 STATIC_COMPONENTS_LINKER_PATH = -LIBPATH:$(DEPTH)/staticlib

--- a/im/build.mk
+++ b/im/build.mk
@@ -31,27 +31,35 @@
 # 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 *****
 
+ifndef COMM_BUILD
+
 ifndef LIBXUL_SDK
 include $(topsrcdir)/toolkit/toolkit-tiers.mk
 endif
 
 TIERS += app
 
+else
+
+TIERS += app
+
 tier_app_dirs += \
   purple \
   instantbird \
   $(NULL)
 
+endif
+
 
 installer:
 	@$(MAKE) -C instantbird/installer installer
 
 package:
 	@$(MAKE) -C instantbird/installer
 
 install::

--- a/im/installer/Makefile.in
+++ b/im/installer/Makefile.in
@@ -103,25 +103,25 @@ MOZ_NONLOCALIZED_PKG_LIST = \
 MOZ_LOCALIZED_PKG_LIST = $(AB_CD)
 
 DEFINES += -DAB_CD=$(AB_CD)
 
 ifdef MOZ_PKG_MANIFEST_P
 MOZ_PKG_MANIFEST = packages-static
 
 $(MOZ_PKG_MANIFEST): $(MOZ_PKG_MANIFEST_P)
-	$(PERL) $(topsrcdir)/config/preprocessor.pl $(DEFINES) $(ACDEFINES) $< > $@
+	$(PERL) $(MOZILLA_SRCDIR)/config/preprocessor.pl $(DEFINES) $(ACDEFINES) $< > $@
 endif
 
 ifneq (,$(filter mac cocoa,$(MOZ_WIDGET_TOOLKIT)))
 MOZ_PKG_MAC_DSSTORE=branding/dsstore
 MOZ_PKG_MAC_BACKGROUND=branding/background.png
 MOZ_PKG_MAC_ICON=branding/disk.icns
 #MOZ_PKG_MAC_RSRC=branding/license.r
 MOZ_PKG_MAC_EXTRA=--symlink "/Applications:/ "
 endif
 
-include $(topsrcdir)/toolkit/mozapps/installer/packager.mk
+include $(MOZILLA_SRCDIR)/toolkit/mozapps/installer/packager.mk
 
 installer: removed-files
 ifdef INSTALLER_DIR
 	$(MAKE) -C $(INSTALLER_DIR)
 endif

--- a/im/makefiles.sh
+++ b/im/makefiles.sh
@@ -29,24 +29,24 @@
 # 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 *****
 
-. "${srcdir}/purple/makefiles.sh"
-
+if [ "$COMM_BUILD" ]; then
 add_makefiles "
 instantbird/Makefile
 instantbird/app/Makefile
 instantbird/app/profile/Makefile
 instantbird/app/profile/extensions/Makefile
 instantbird/base/Makefile
 instantbird/base/content/Makefile
 instantbird/locales/Makefile
 instantbird/themes/Makefile
 instantbird/themes/winstripe/Makefile
 instantbird/themes/winstripe/instantbird/Makefile
 instantbird/installer/Makefile
 instantbird/installer/windows/Makefile
 "
+fi