Because using ssh is much easier then telnetting to the remote machine and changing the enviroment variables (and also has less room for error).
SSH client installed on your machine, ssh server running on the remote machine. For the most part, a default install of both will allow this to work properly.
Start X with your favorite window manager (KDE, GNOME, Afterstep, etc). Open up a terminal. Type the following line
ssh -X email@example.com [ENTER]or
ssh -X -l user remote.machine [ENTER]enter your password when prompted. (It may ask you if you want to accept the remote key, for the most part, it is ok to say yes here). The option "-l" tells ssh that you are going to use a user other than the one you use on your local machine. If you use the same username on both the local and remote machines, then
ssh -X remote.machine [ENTER]is acceptable and the minimum needed to make this work. The "-X" option tells ssh that it will be using x-forwarding. To launch a remote app, type the name of the app on the command line, so, entering
netscapeat this point will launch netscape on the remote machine but will show up on your screen. It doesn't matter what Unix or processor the remote machine is running.
When entering commands, it is probably useful to run them in the background so that you can launch multiple applications at the same time -- for example entering
netscape &on their own lines will launch netscape, the gimp, and gaim and still give you a command prompt. This HOW-TO is instead of the how-to http://www.terrasoftsolutions.com/support/solutions/ydl_general/remote_apps.shtml Which covers telneting. However, if ssh is not installed on the server and there is no way to get it installed, you will have to use the methods in the link above.
This HOWTO was written by Bradley Molnar