X11 for Mac OS X

NOTE:  The Securing X Windows document from DOE-CIRC applies to the use of basic OS/X X11 commands.

Improper configuration of X Windows can allow the compromise of your password and the exposure of your display. Please secure your system's X services!

A primary precaution is that the command "xhost +" should NOT be used. It gives any computer access to your display and keyboard.


As of Mac OS X 10.7, Apple no longer ships an installed X11 client. The supported solution for Apple and for JLab is to install XQuartz. This software is installed as part of the JLAB Cue Software for Macs, however, if your Mac was not configured by the Computer Center, the software can be downloaded from the homepage for the XQuartz project, which is located here:  http://www.xquartz.org/

Simply download the latest version, mount the dmg file, and install the package. Once you do, you will be prompted to log out and log back in to make XQuartz you default X11 Client. Once XQuartz has been installed and you have logged back in, simply use the following command in the Terminal app (Go > Utilities > Terminal):

ssh -X hostname

With hostname indicating the Unix/Linux Server that you would like to connect to, i.e., jlabl1, jlabl2, etc. After you've connected to the server of choice, type the appropriate command to start the GUI software of your choice. If you have any questions, please feel free to contact the Computer Center Help Desk.