Operating system. Simply, a program that runs your
computer. Examples of an operating system are CP/M, DOS,
Windows, Mac OS,
Linux, and Palm OS, though there are many more. One will oftentimes become overly attached to their OS, preaching it as though it were a religion and shunning all who use anything even slightly different.
Man: My OS of
choice is Windows XP.
Woman: My OS of choice is
Mac OS X.
Man & Woman: (killing eachother)
Supa-Nerd: My OS of choice is
CP/M! 8086 FOREVAH!!!