Robert G. Ferrell
Once upon a time, there was only one layer: the operating system. It was your first and best means of exchanging ones and zeroes with the processor, the mystical heart of your computer. You wrote code, compiled it or fed it to an interpreter, and something interesting usually happened. Well, my code always made something interesting happen, but my threshold for interesting includes power cycling and printers with a pronounced tendency to spit out page after page of nonsense. I also evinced a preternatural knack for triggering crash dumps that literally caused the machine, not to mention any clued-in onlookers, to shudder.