Hello, I had posted a comment/question a few months back when I had initially installed Mountain Lion on my mac regarding iXAFS compatibility with XQuartz and the new OS not supporting X11 anymore. Since then I have received a few comments back and I found one solution to be the best. This was originally sent by Tsu-Chien Weng from SSRL (tsuchien@slac.stanford.edu). Please find the following solution below. Once you install XQuartz the rest will be done in the Terminal.app. This is a one time solution and I havent had any trouble thus far with the program. Hope this works as well for everyone else as it did for me. 1. Install XQuartz from http://xquartz.macosforge.org/landing/ 2. open Terminal.app 3. cd /Applications/Utilities 4. sudo mkdir X11.app 5. cd X11.app 6. sudo ln -s ../XQuartz.app/Contents Thank you, Kyler J. Carroll, Ph.D. Assistant Project Scientist Department of NanoEngineering University of California, San Diego