--- startx.orig	2016-05-28 07:46:39.000000000 -0700
+++ startx	2016-05-28 08:15:49.000000000 -0700
@@ -80,6 +80,10 @@
     defaults write $X11_PREFS_DOMAIN nolisten_tcp -bool true
 fi
 
+if ! defaults read $X11_PREFS_DOMAIN enable_iglx > /dev/null 2>&1 ; then
+    defaults write $X11_PREFS_DOMAIN enable_iglx -bool false
+fi
+
 # First, start caching fonts
 if [ x`defaults read $X11_PREFS_DOMAIN cache_fonts` = x1 ] ; then
     if [ -x $bindir/font_cache ] ; then
@@ -107,6 +111,9 @@
     defaultserverargs="$defaultserverargs -nolisten tcp"
 fi
 
+if [ x`defaults read $X11_PREFS_DOMAIN enable_iglx` = x1 ] ; then
+    defaultserverargs="$defaultserverargs +iglx"
+fi
 
 # The second check is the real one.  The first is to hopefully avoid
 # needless syslog spamming.