John Carmack

John D. Carmack II (born August 21, 1970) is an American computer programmer and video game developer. He co-founded the video game company id Software and was the lead programmer of its 1990s games Commander Keen, Wolfenstein 3D, Doom, Quake, and their sequels. Carmack made innovations in 3D computer graphics, such as his Carmack's Reverse algorithm for shadow volumes.

In 2013, he resigned from id Software to work full-time at Oculus VR as their CTO. In 2019, he reduced his role to Consulting CTO so he could allocate more time toward artificial general intelligence (AGI). In 2022, he left Oculus to work on his AGI startup, Keen Technologies.

Carmack was born in Shawnee Mission, Kansas, the son of local television news reporter Stan Carmack. He grew up in the Kansas City metropolitan area, where he became interested in computers at an early age. He attended Shawnee Mission East High School in Prairie Village, Kansas and Raytown South High School in nearby Raytown, Missouri.

Carmack was introduced to video games with the 1978 shoot 'em up game Space Invaders in the arcades during a summer vacation as a child. The 1980 maze chase arcade game Pac-Man also left a strong impression on him. He cited Nintendo designer Shigeru Miyamoto as the game developer he most admired.

As reported in David Kushner's Masters of Doom, when Carmack was 14, he broke into a school with other children to steal Apple II computers. To gain entry to the building, Carmack concocted a sticky substance of thermite mixed with Vaseline that melted through the windows. However, an overweight accomplice struggled to get through the hole and instead opened the window, setting off a silent alarm and alerting police. Carmack was arrested and sent for psychiatric evaluation. He was sentenced to a year in a juvenile home. He attended the University of Missouri–Kansas City for two semesters before withdrawing to work as a freelance programmer.

Softdisk, a computer company in Shreveport, Louisiana, hired Carmack to work on Softdisk G-S (an Apple IIGS publication), introducing him to John Romero and other future key members of id Software such as Adrian Carmack (no relation). Later, Softdisk would place this team in charge of a new, but short-lived, bi-monthly game subscription product called Gamer's Edge for the IBM PC (DOS) platform. In 1990, while still at Softdisk, Carmack, Romero, and others created the first of the Commander Keen games, a series that was published by Apogee Software, under the shareware distribution model, from 1991 onwards. Afterwards, Carmack left Softdisk to co-found id Software.

Carmack has pioneered or popularized the use of many techniques in computer graphics, including "adaptive tile refresh" for Commander Keen, ray casting for Hovertank 3D, Catacomb 3-D, and Wolfenstein 3D, binary space partitioning which Doom became the first game to use, surface caching which he invented for Quake, Carmack's Reverse (formally known as z-fail stencil shadows) which he devised for Doom 3, and MegaTexture technology, first used in Enemy Territory: Quake Wars. Quake 3 popularized the fast inverse square root algorithm.

Carmack's engines have also been licensed for use in other influential first-person shooters such as Half-Life, Call of Duty and Medal of Honor: Allied Assault. In 2005, Carmack developed his first game for mobile phones, Doom RPG.