diff -ur portage-orig/profiles/use.local.desc portage/profiles/use.local.desc
--- portage-orig/profiles/use.local.desc        2005-05-20 11:58:06.000000000 +0800
+++ portage/profiles/use.local.desc     2005-05-20 12:03:46.000000000 +0800
@@ -973,3 +973,4 @@
 x11-wm/windowmaker:modelock - Enable XKB language status lock support. README says: "If you don't know what it is you probably don't need it."
 x11-wm/windowmaker:vdesktop - Enable NEWTWM style virtual desktop support.
 x11-wm/wmii:cairo - use cairo as rendering backend (instead of Xlib)
+xfce-base/xfwm4:composite - Enable the built in compositor (uses the XComposite extension)
diff -ur portage-orig/xfce-base/xfwm4/xfwm4-4.2.2.ebuild portage/xfce-base/xfwm4/xfwm4-4.2.2.ebuild
--- portage-orig/xfce-base/xfwm4/xfwm4-4.2.2.ebuild     2005-05-20 11:54:26.000000000 +0800
+++ portage/xfce-base/xfwm4/xfwm4-4.2.2.ebuild  2005-05-20 12:03:54.000000000 +0800
@@ -4,8 +4,12 @@

 DESCRIPTION="Xfce 4 window manager"
 KEYWORDS="~alpha ~amd64 ~arm ~hppa ~ia64 ~mips ~ppc ~ppc64 ~sparc ~x86"
+IUSE="composite"

 RDEPEND="~xfce-base/xfce-mcs-manager-${PV}"
-XFCE_CONFIG="--enable-randr --enable-compositor"
+XFCE_CONFIG="--enable-randr"
+if use composite
+then XFCE_CONFIG="${XFCE_CONFIG} --enable-compositor"
+fi

 inherit xfce4
\ No newline at end of file