Sure. On your Linux box to display a clock on your Linux box, you can do this:
xclock -display :0
env DISPLAY=:0 xclock
If you wanted to instead run xclock and direct it to display on a remote machine, you’d do one of the following:
xclock -display remotehostname:0
env DISPLAY=remotehostname:0 xclock
You can do the same thing with GL apps, assuming that all of the GL commands you’re using have GLX “wire protocol” forms AND you have permission to connect to the remote display. For instance:
glxgears -display remotehostname:0
env DISPLAY=remotehostname:0 glxgears
There are several ways to set up permission to access to the remote display, including just using ssh and letting it “tunnel” X/GLX protocol through the SSH connection.
A few random links:
The lingo to google for is “remote x display”.