id Tech 4 is a game engine developed by id Software, known for powering popular first-person shooters like Doom 3. Released in 2004, it introduced advanced graphics features, including real-time lighting and shadowing, which enhanced the visual quality of games. The engine supports various platforms, including Windows, Linux, and Xbox. It utilizes a modular design, allowing developers to create custom content easily. id Tech 4 also features a robust physics engine, contributing to realistic interactions within game environments, making it a significant advancement in game development technology at the time.