X11 for Windows and Mac

X11 is a remote-display protocol used by Linux/Unix machines, including the Linux machines at Thayer. By running an X11 program (known as a server) on your computer, you can access graphical Linux programs remotely through an SSH client. In addition some *nix applications ported to macOS do not run natively under the macOS GUI and require X11.

Terminology Note: The program displaying graphics on your local machine is called an X Server, and the process on the remote end is called an X client. Yes, this may be backwards from what you might first expect.  You can think of this program providing local graphics services for client programs running remotely.


  • Xming Open-source, free, and full-featured.


To install X11 on macOS, download and install the XQuartz Application from: www.xquartz.org


Another method for accessing graphical programs remotely from our Linux compute servers is FastX. This program allows you to run a full remote desktop which can be disconnected and reconnected while graphical applications continue to run. FastX  can also be much faster that X11 forwarding, especially over slower connections. For more information about downloading and setting up FastX, see this page: FastX