Most unofficial videogame ports

Developed by PC shooter specialist iD Software and released in 1993, Doom has been unofficially ported to at least 110 different platforms, according to research conducted by the It Runs Doom blog. These range from ports to platforms designed to run custom software, such as the Ouya, to novelty ports on things like a pregnancy test and superstar DJ Deadmau5′s 'Cube' stage. Doom has even been used to create a security flaw demo for a John Deere tractor!

<em>Doom</em> was deliberately programmed in such a way as to encourage modders to tinker with it. A large community of amateur developers built up around the game during the 1990s, developing additional content and mods. In 1999, with iD having moved on to different, more capable game engines, they released iD Tech 1 under the GNU General Public License (an open-source license), allowing this community to continue to update and modify not just level data files, but the engine itself. It is this flexibility that has made it possible to contually adapt the game's code for new hardware.