If your SSH'ing to a linux machine from a linux machine just issue the command:
# ssh -X username@ipaddress
If your SSH'ing to a linux machine from a Windows machine you need get the following:
Xming X Server
PuTTY
You might also need to install some fonts found here (I however didn't need to do this):
Fonts
- Now just install Xming and the Fonts (if the Fonts are needed) into the default directory.
- Then launch PuTTY and enter in the username@ipaddress into the "Host Name" field
- Go to the Connection>SSH>X11 section in PuTTY and check the "Enable X11 forwarding" option
- Also, if needed, set the "X display location" to localhost:0
Once you connect you will be able to issue commands in the command line as you would normally but also run programs that have a GUI. A really cool feature is that the windows are created in your local OS unlike VNC and RDP where the windows are bound inside the Remote Desktop Application window.
Note: The SSH Deamon running on the server might need to be configured to allow X11 Forwarding. Just do a google search to get this information (it generally just requires you to uncomment a line in a configuration file).
Enjoy