With one third of the game, nine levels, distributed as shareware, Doom was played by an estimated 10 million people within two years of its release, popularizing the mode of gameplay and spawning a gaming subculture. In addition to popularizing the FPS genre, it pioneered immersive 3D graphics, networked multiplayer gaming, and support for customized additions and modifications via packaged files in a data archive known as „WADs“. Now one geek has managed to hack a few toasters to use as controllers for the game.
The series started to lose mainstream appeal as the technology of the Doom game engine was surpassed in the mid-1990s, although fans have continued making WADs, speedruns, and modifications to the original. The franchise again received popular attention in 2004 with the release of Doom 3, a retelling of the original game using new technology, and an associated 2005 Doom motion picture.
Source: http://www.reddit.com/r/gaming/comments/2s0kv7/how_to_mod_any_toaster_to_control_pc_games_in_3/
