Hi,

actually the X11 issue is not so hard to solve. X11 is part of the 'Optional Installs' package that comes on DVD/CD with every Mac. So you could give your users some instructions on how to install that. Also I've seen a few newer machines (OsX 10.5) which had X11 installed by default and even started X11.app automagically when the user opened my pp-packed Tk application.

Cheers, Christoph