A little background
The current latest version of Matlab is 2012a. It was released for Mac OS X Lion (10.7) so requires X11 to provide the GUI. However, with the release of Mac OS X Mountain Lion (10.8), X11 is no longer provided by default from Apple. This poses a bit of a problem for Matlab 2012a.
What to do with Matlab 2012a on Mountain Lion?
While Mountain Lion doesn't have X11 and Apple isn't providing their version of X11, they are providing development support to the Open Source project that the Apple X11 was based off of: XQuartz.
