Development of Doom
The development of "Doom", a first-person shooter video game by id Software, began in November 1992 and continued until the game was released in December 1993. Seven people worked on "Doom", which is considered one of the most significant and influential titles in video game history. The initial development team was programmers John Carmack and John Romero, artists Adrian Carmack and Kevin Cloud, and designer Tom Hall; late in development Hall was replaced by Sandy Petersen and programmer Dave Taylor was added to the team. The music and sound effects were created by Bobby Prince.
Doom WAD
John Carmack, lead programmer at id Software, designed the "Doom" internals from the ground up to allow players to extend the game. For that reason, game data such as levels, graphics, sound effects, and music are stored separately from the game engine, in "WAD files". This allowed players to make their own data without making any modifications to the engine. According to "Doom"s initial design document, WAD stands for "Where's All the Data?".