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id Software
Founded	February, 1991
Located	Texas, USA
Website	http://www.idsoftware.com/
Wikipedia has more about this subject: Id Software

id Software has been working since 1991, with the central office in Texas. It has since released many games known to most players: Doom, Quake, Wolfenstein, among other very renowned releases.

The company has made several other major contributions to actual PC gaming, like Internet gaming and mod communities, but most important of all, the legitimization of shareware computer games, which, along with the already mentioned mod communities, have given the FPS a boost in the gaming industry.