"There is a scene in "The Color of Money" where Tom Cruse [sic] shows up at a pool hall with a custom pool cue in a case. "What do you have in there?" asks someone. "Doom." replied Cruse with a cocky grin. That, and the resulting carnage, was how I viewed us springing the game on the industry." - John Carmack, 2005Doom is considered by many as the breakthrough first person shoot-em-up. Created by John Carmack in the 1993 for Id Software, Doom made all the impact on the gaming market that Carmack a hoped for. The game was highly touted for its 3D rendering engine (which isn't strictly 3D due to an inability to look up) but perhaps more importantly, for its extensibility by the users. The program was initially released as shareware which allowed it to spread to and estimated 10million computers. Perhaps one of the key points for its continued success is that the engine that it was based on and subsequently other derivative engines, such as the Quake II engine, were released under GNU/GPL licenses. This continued openness and interaction with the fanbase has not only helped develop an entire subculture but given the game a life far exceeding that of a normal product cycle and has created sequels, spin-offs, comics, novels and even a Hollywood movie.
As with much in the games industry it wasn't all fun and rendering engines. The freely available nature of the game and the introduction of multiplayer Deathmatch mode over networks meant that productivity in many companies was impacted with both network clogging and staff spending all their time playing each other. Though that may have caused a headache to network admins, the real controversy surrounding Doom was the gore, gibs, satanic imagery and general level of violence. Some described the games as simulated mass murder but nothing could have been more harrowing than the line "It's gonna be like fucking Doom man" spoken by Eric Harris before engaging in the Columbine High School massacre.