Kevin Cloud

John Carmack built the engine from scratch.

The levels were mostly John Romero's and Sandy Petersen's, and the art came from Adrian Carmack and Kevin Cloud.

The title's nicked from The Color of Money, where Tom Cruise gets asked, uh, what's in his case, and answers, "Doom?" You play a space marine stuck on the moons of Mars, shooting through demon-infested bases.

Uh, Knee-Deep in the Dead is the free first episode.

Amazingly, that was added only weeks before launch.

Four players could link up over a network.

Romero named it Deathmatch, and Kevin Cloud gave us the word fragging.

Within a matter of hours, universities had started banning it for jamming their, uh, networks.