Hi,
I hope my question is easy to answer. I used to use AIX to log into other aix machines to run scientific software. I could log in and then run programs on my aix machine that required other graphsics windows to open such as graphing utilites.
However I am now using a linux box for this and when I try to run the same programs when logged in remotely on other unix machines from my linux box the window won't open for the program so I can't run it. What do I have to do to fix this?

If you're trrying to run a program in X, then you need to set up a VNC server on your Linux box. Go to the TightVNC web page and download their software on both computers and install it. Log on to your linux box (remotely if you want to) and type:So, for instance, you want 16 bit color with an 800 by 600 desktop, you type: and it will return something like . Now you open VNC Viewer on your other computer by typing where ip address is the ip of your linux box and port is the number after the colon that the computer printed after using vncserver. For instance: to match up with my earlier example. When the X Server loads, you can run any program in X that works. Another way to access the VNC Server is to type: where ip address is the ip of your linux box and # is the port number previously mentioned. For instance: in a browser will open an applet for it.

I hope I made this clear.

VNC is one way to go, but you can use the built in features of the X server as well. If you use ssh to login to the remote computer, you can use ssh's built-in X-forwarding option that tells the remote computer to forward all X information to your box.

As well, you can setup xdm (kdm,gdm) to allow you to get a login screen remotely for a system. There are several guides on the internet for this, just do a goole search for "Remote X login".