1 Spanners: Ah, a gem. This is probably it. Now to issue the command and see if we can get out of cyberspace.
2 Spanners: System.exit(0);
3 {Scene change: back to reality}
3 Spanners: Cool! It worked! We're back in reality!
3 Iki Piki, Paris: Yay!
4 Serron: "System.exit(0);"?
4 Spanners: You expected "Computer, end program" or something stupid like that?

2012-02-15 Rerun commentary: System.exit(0); is the command to end a program in the language Java, which was my primary programming language at the time I wrote this strip. I don't think I've used Java since... soon after this strip was originally published.

Nowadays I primarily write code in python, in which the same command would be the very different: sys.exit(0)

The 0, by the way, if you're not familiar with program exit codes, is a code to indicate "no error". In other words, ending the program in the normal way it is expected to end. If you encounter an error condition inside your code, you can issue the same exit() command, but with a different number, to indicate exactly what error occurred. It's up to the surrounding operating system to interpret and report the error code for you. Or it could just report the number and let you look it up.