An important command line option is -display, which you can use to specify the display on which you want the client's output to appear. You can use this option as an alternative to setting the $DISPLAY environment variable before starting the application.
For example, if you want to run the xbiff client,
and display its output on a remote server on a machine
named scooter, you would enter:
xbiff -display scooter:0.0 &
where ``scooter'' is the name of the remote host machine.