DOOM is a series of first-person shooter video games developed by id Software, and related novels, comics, board games, and major film adaptation. Doom is considered to be one of the pioneering first-person shooter games, introducing, to IBM-compatible computers, features such as 3D graphics, third-dimension spatiality, networked multiplayer gameplay, and support for player-created modifications with the Doom WAD format. Since its debut, over 10 million copies of games in the Doom series have been sold.