Connect from Linux to an X server

This trick is a very simple but useful one: if you want to open an X session in your Linux computer from other UNIX computer, like if you were in front of its console, then you can run as root a command like this:

X -query unixserver :1

This way you're telling X to connect to the greeter running in unixserver and display it in graphic console number one (you might be running an X session in :0 already). In order to work this the greeter in the UNIX computer must be running and listening for connections; for example, it would be xdm, kdm or gdm in Linux, dtlogin in HP-UX and so on.