id Software

id Software is a Texas-based developer founded in 1991 and part of Bethesda/ZeniMax since 2009. Within a few years it released Wolfenstein 3D, Doom, and Quake — a rapid-fire sequence that helped popularize first-person action on PCs and seeded mod communities that influenced engine licensing for the rest of the decade.

The 1993 Doom shareware model and open file formats invited player-made levels, total conversions, and competitive speedrunning earlier than many publishers were comfortable acknowledging. Ports to new hardware still appear because the original codebase is compact enough to run on unexpected devices — a running industry in-joke that doubles as engineering flex.