Doom (occasionally typeset as DOOM) is a 1993 first-person shooter computer game by id Software that is a landmark title in the first-person shooter video game genre, and in first person gaming in general. It is widely recognized for pioneering immersive 3D graphics, networked multiplayer gaming on the PC platform, and support for custom expansions (WADs). Distributed as shareware, Doom was downloaded by an estimated 10 million people within two years, popularizing the mode of gameplay and spawning a gaming subculture; as a sign of its effect on the industry, games from the mid-1990s boom of first-person shooters are often known simply as "Doom clones". Its graphic and interactive violence has also made Doom the subject of much controversy reaching outside the gaming world. According to GameSpy, Doom was voted by industry insiders to be the greatest game of all time in 2004. [source:wikipedia]