Well, I can get a mild version of a virtual screen on my Fedora system on the GUI with Ctrl Alt - That's a minus sign after the Alt. The software screen is larger than the area of the monitor's screen and you can view the areas outside of the monitor screen by using the mouse. On the old Slackware distributions you could get a software virtual screen about 50 % larger than the monitor's screen. I found that useful and I miss it since neither Slackware 10, nor Fedora seem to have it. Or maybe I don't know how to activate it. I hope that explains it.