Because I know that a lot of MAC users here, I like to announce that the latest guitairx version is now also available for MAC OSX.
 maciimacii  have create a guitarixOSX installer package which comes with all  runtime libraries included, so guitarix should (theoretically) run on any OSX system without any additional library installs or library compiling. It was compiled and tested with X11 XQuartz 2.3.6 (Snow Leopard 10.6.8)

you can get the package here:
http://sourceforge.net/projects/guitarix/files/OSX/guitarixOSX%200.24.zip/download

more info or contact to maciimacii here:
http://sourceforge.net/apps/phpbb/guitarix/viewtopic.php?f=3&t=4215

greets
hermann