Displaying an X Application from a Remote Machine
The ssh and slogin commands used to connect to remote hosts should automatically forward X Windows. However, if for some reason you do need to set up X Windows forwarding, follow these steps:
First, give permission on the machine you're sitting at for the remote machine to open the window. Use xhost +remote_machine_name, where <remote_machine_name> is the name of the remote machine.
Next, connect to the remote machine and set the DISPLAY environment variable on the remote machine to the display on the machine you're sitting at. If you're using the C or tcsh shell, you'd do setenv DISPLAY local_hostname:0.0, and in the Bourne or bash shell, you'd do DISPLAY=local_hostname:0.0; export DISPLAY. Now you can display X back to the machine you're sitting at.
When you are finished with your session, be sure to remove permission from the machine you're sitting at. Use the command xhost -remote_machine_name.
Changing the X Resource Database
The xrdb command is used to modify your X resource database. Read the man pages for xrdb for more information. Read the man pages for the particular application you want to change to find out what the correct resource name is.
Listing Available Fonts
You can use the xlsfonts command to list X windows fonts. You can use the xfd command to display all the characters of a particular font. You can use the xset -q command to get a listing of your current font path.
Remapping the Keyboard
Use xmodmap to remap the keyboard. See the man pages.
More Information about the X Window System
The comp.windows.x.apps FAQ answers common questions about X Windows.