This was brought up last month, and I said functionality was "close" ... it's pretty much here now in 2.3.2_rc5, so if you want to have an X11 server dedicated to a single application (gimp for example), you can do that like this: 1) Copy X11.app to X11Gimp.app 2) edit X11Gimp.app/Contents/Info.plist and change the XFBundleIdentifier from "org.x.X11" to "org.x.X11.gimp" 3) Create a xinitrc.d script to handle starting gimp: $ sudo nano -w /usr/X11/lib/X11/xinit/xinitrc.d/95-gimp.sh # Now paste this: if [ "$X11_PREFS_DOMAIN" = "org.x.X11.gimp" ] ; then quartz-wm & exec gimp fi 4) Make that script executable: $ sudo chmod 755 /usr/X11/lib/X11/xinit/xinitrc.d/95-gimp.sh Hope that helps whoever wanted it (sorry, I can't find the original email)... There is just one bug that I know of. X11.app doesn't know which quartz-wm belongs to it, so you might have some bugs with Exposé on the second, third, etc X11.apps ... --Jeremy