In brief
Four employees of Softdisk, a Texas publisher of disk magazines (programmers John Carmack and John Romero, designer Tom Hall, and artist Adrian Carmack), made games for themselves in the evenings, and on February 1, 1991, they formally turned this into a company, id Software. In three years they went from Commander Keen, published by someone else through Apogee, to Wolfenstein 3D and Doom: games that did more than sell well: they rebuilt the first-person shooter genre and turned openness to mods and the licensing of their own engine into separate sources of money. In 2009 the company was bought for $150 million by ZeniMax Media, under whose wing id works to this day.
How it started (the founders)
All four met not as entrepreneurs but as salaried employees of Softdisk, a company that put out monthly disk magazines for DOS computers. Inside it, Carmack and Romero ran an unofficial group, "Ideas from the Deep," making games beyond their work plan. The turning point came in September 1990, when Carmack found a technique for smooth byte-by-byte screen scrolling on the PC, something no one had managed on that hardware before; with this technique they built a demo in the spirit of Super Mario Bros. 3 and soon after a full game, Commander Keen, published on December 14, 1990, through the publisher Apogee, before id even existed as a company. It was the first royalty check from Apogee that convinced the team to leave Softdisk and found id Software on February 1, 1991.
The first year was spent on the move: from Shreveport (where Softdisk was also based) to Madison, Wisconsin, in September 1991, and on April 1, 1992, to Mesquite, Texas, where the company settled for years. Alongside the organizational bustle ran a technical evolution: even before Wolfenstein 3D, id twice tried out the idea of a first-person shooter on its own engine, with Hovertank 3D in April 1991 and Catacomb 3-D in November 1991, both again published by Softdisk. These were not side experiments but direct prototypes: the Hovertank engine grew into wall texturing in Catacomb 3-D, and then into doors and moving walls in Wolfenstein 3D.
Year-by-year timeline
- 1990-12-14: Commander Keen comes out through Apogee; id as a brand exists before id as a company fact
- 1991-02-01: four Softdisk employees formally found id Software in Shreveport, Louisiana fact
- 1991-04: Hovertank 3D, id's first first-person game, on an early raycasting engine fact
- 1991-09: the move to Madison, Wisconsin fact
- 1991-11: Catacomb 3-D, an engine with wall texturing and a direct prototype of Wolfenstein 3D fact
- 1992-04-01: the move to Mesquite, Texas fact
- 1992-05-05: Wolfenstein 3D is released; fans almost immediately write map editors and hack the shareware file; Apogee sees this as a threat to sales, id does not fact
- 1993 (summer, early August): Tom Hall leaves after a conflict with Carmack and Romero over the amount of story in the "Doom Bible" fact
- 1993-12-10: Doom is released; an attempt to upload the shareware version to the University of Wisconsin FTP server at midnight brings the network down under a rush of about 10,000 simultaneous downloads fact
- 1994-10-10: Doom II comes out in retail through GT Interactive; more than 250,000 preorders, more than 500,000 copies in the first four months, and more than 2 million copies in total fact
- 1996-06-22: Quake is released; the same year its engine is licensed by the newly founded Valve for the future Half-Life fact
- 1996-08-06: John Romero leaves id soon after Quake, amid a conflict with Carmack over the game's direction fact
- 1997-12-23 / 1999-10-03: the Doom source code is first published (without the GPL, because of the sound library's license); a full GNU GPL license was agreed with Carmack only in 1999 fact
- 2009-06-23 / 06-24: ZeniMax closes the purchase of id Software's assets on June 23 (the date is confirmed by both Carmack's lawsuit and the SEC Form D), and the announcement comes a day later; the amount is $150 million per the text of Carmack's lawsuit (2017), including a $45.1 million note to Carmack personally
Lesser-known but significant facts
- Doom was not id's first attempt at a 3D shooter but its third. Hovertank 3D (April 1991) and Catacomb 3-D (November 1991) came out more than two years earlier and were already first-person games with a primitive 3D engine; they were simply published quietly, through Softdisk, rather than under id's own promoted name.
- Apogee and id disagreed about fans hacking Wolfenstein 3D. Apogee believed that mods and map editors cut into sales, since people got far more "free" levels than intended; id's developers, on the contrary, were glad of the hacking and decided not to hinder such activity but to encourage it in future games.
- By the end of 1993 Wolfenstein 3D had sold more than 100,000 copies, earning id about $8 on each, against roughly $2 per Nintendo cartridge: a direct comparison of the economics of PC shareware with the console cartridge market of that era.
- Doom's openness was a decision, not an accident of hacker ideology from day one. Carmack deliberately separated the game's levels and assets from the engine in WAD files, even more thoroughly than in Wolfenstein 3D, and released the format documentation on release day; but fully open source code under the GPL appeared only in 1999, after the author of one of the mods lost his work when a disk failed.
- Tom Hall's departure in 1993 was a conflict not about money but about story. Hall wrote the "Doom Bible" with a backstory and cutscenes; Carmack and Romero argued for a minimum of story for the sake of the game's pace, a philosophy characteristic of id that would later harden into Carmack's far blunter statement about story in games.
Legend vs. the record
- Legend: Doom was the first 3D shooter. That is what Doom is usually called in retrospectives and pop culture. The record: id's own earlier games, Hovertank 3D (April 1991) and Catacomb 3-D (November 1991), were already first-person shooters on a primitive 3D engine, more than two years earlier. Wolfenstein 3D (May 1992) added a modern raycasting engine a year and a half before Doom, and the competitor Ultima Underworld (March 1992) came out even earlier with full 3D geometry and sloped surfaces and pushed Carmack himself to build a competitive answer. Verdict: Doom did not open the genre; it perfected and took to a mass audience what id itself (and its competitors) had been working out over the previous three years.
- Legend: Doom was given away free and earned nothing. This is a common simplification of the first-episode-free model. The record: right after release, shareware registrations brought in about $100,000 a day (Kushner, "Masters of Doom"); only the first of three episodes was free, and the retail Doom II through GT Interactive collected more than 250,000 preorders in 1994 and eventually sold more than 2 million copies. Verdict: the hook was free, not the product; the funnel worked so well that the take ran to hundreds of thousands of dollars a day in the very first days.
- Legend: id opened Doom to mods out of pure altruism and Carmack's hacker ideology from day one. The common version paints Carmack as an idealist who decided from the very start to share the code with the world. The record: id's reaction to the hacking of Wolfenstein 3D was positive (unlike Apogee's) and pushed it to design Doom to be more moddable, and id's press release of January 1, 1993, already publicly promised, 11 months before the game came out, that DOOM would be released as an open game and that the company would give file formats and technical documentation to anyone who wanted them. Open source code under the GNU GPL, however, appeared only in 1999, after the author of the glDoom mod lost his changes when a disk failed. Verdict: Doom's openness grew in steps, from not getting in hackers' way in 1992, to a public promise of openness in 1993 marketing, to the GPL in 1999, rather than being a single gesture at launch.
The first growth lever
The lever was not the game itself but the combination of two decisions: a free first episode and a deliberately open architecture for mods. In the very first days after the December 1993 release, Doom's shareware registrations brought in about $100,000 a day, even though, by the estimate of researchers of the topic, those who downloaded the first episode for free outnumbered those who paid by an order of magnitude: installs running far past eight figures against 2–3 million copies of the shareware version sold. A minority paid, but it was the free majority that created word of mouth and demand for the sequel. The second layer of the lever kicked in a year later: the retail release of Doom II in October 1994 collected 250,000+ preorders and sold more than 2 million copies, as the shareware hype of 1993 converted into 1994 retail through a channel Wolfenstein 3D had not had. The same free layer worked for retention: open WAD files let fans make levels and mods from day one, extending the game's life with no marketing budget.
The paired story
Without Apogee Software, id would have had no starting capital: the publisher's advance and royalties for Commander Keen and Wolfenstein 3D funded the team in 1990–1992 (the deal details are in the Apogee dossier). The pair split over the very thing it grew out of: its attitude toward fans hacking the game. When players started breaking into the shareware file and building their own levels after Wolfenstein 3D, Apogee as publisher saw a threat to sales; id took the opposite position, welcomed the hacking, and in Doom deliberately made modification easier, with open WAD files and format documentation on release day. The split over distribution was economic as well: id decided that Apogee could not handle the volume of phone orders for Doom and hired a third-party company. The contrast: Apogee perfected the funnel of a free piece leading to a paid sequel and tried to control how much was free, while id widened the free layer through openness to mods, a bet the publisher considered risky and id saw as working for reach and loyalty.
Parallels today (projects from the catalog)
- OpenSEO (
openseo) follows the same logic as id opening the WAD format: a free open-source layer (the self-host version) became the main growth channel, with 1,600+ GitHub stars in two months organically, before the paid launch. The difference between the eras: id opened a file format inside a closed game, while OpenSEO's entire code is open, and the company makes money on cloud data and hosting on top of it. view this project's dossier → - Social Fetch (
social-fetch) is a direct parallel to the model of technology licensing as a second business: the API grew out of internal infrastructure the founder was already using for his own products and then became a separate product for other developers and AI agents, exactly what id did with the Quake engine, originally built for its own game and then licensed to Valve for Half-Life. The difference: id's deal was a one-off, under contract with a single studio, while Social Fetch is a self-serve API for anyone who pays. view this project's dossier →
What a builder can take from this in 2026
- Your product will be hacked and remade anyway, so build that into the architecture in advance. id did not make Doom moddable out of pure altruism; it drew conclusions from how fans were already breaking Wolfenstein 3D and designed its next game so that this worked in its favor.
- A free layer is not charity but the cheapest sales funnel. The gap between the paying minority and the free majority for Doom was an order of magnitude, and it was the free majority that generated the demand that converted into $100,000 a day right after release.
- An internal tool you built for yourself can become a separate business. The Quake engine was built for id's own game and became technology licensed by Valve: a second source of money unrelated to sales of the game itself.
- When a distributor can't keep up with your growth, that's a reason to build your own channel, not to argue. id parted with Apogee for Doom not over a quarrel but out of sober calculation: the audience grew faster than the publisher could process orders.
- Radical openness can be gradual rather than all at once. It took seven years and one specific incident of lost code to get from not getting in modders' way in 1992 to a full GPL in 1999; you don't have to open everything at once for openness to work for growth.
Discrepancies and what we could not verify
- Why John Romero left in 1996. One source says he left voluntarily, another that he was fired for not working hard enough. Carmack's .plan entry of August 8, 1996, saying that Romero was no longer at id, confirms the fact and the date as a primary source but does not choose between the versions of the cause estimate.
- The price ZeniMax paid for id Software: the question was closed on this pass. There is still no official statement of the price from ZeniMax itself, but $150 million is now confirmed by the text of Carmack's lawsuit and, independently, by the SEC Form D.
- The amounts of the id Tech licensing deals (the Doom engine to Raven Software for Heretic/Hexen, the Quake engine to Valve, and others): the fact of licensing is confirmed, but the specific payment figures are not disclosed in any source reviewed [not found].
- Wolfenstein 3D's sales curve over time: more than 100,000 copies by the end of 1993 and more than 250,000 by the end of 1995 per the Apogee dossier do not contradict each other, but the exact growth curve between those dates has not been reconstructed.
- There are now four primary sources: Carmack's .plan entry, id Software's own press release about Doom, Carmack's complaint against ZeniMax, and the SEC Form D; the rest of the material is modern journalistic longreads and encyclopedic indexes.
Sources (primary first)
- John Carmack .plan archive, one of the August 1996 entries (primary source)
- id Software — Doom press release, January 1, 1993 (primary source)
- John Carmack v. ZeniMax Media Inc., complaint, Case No. 3:17-cv-00661-B, 2017 (primary source)
- SEC EDGAR — Form D, ZeniMax Media Inc / Id Software LLC, 2009 (primary source)
- David Kushner, "Masters of Doom" — book excerpt, Game Developer
- "Monsters from the Id: The Making of Doom," Game Developer (a contemporary industry longread from the period of Doom's development)
- FundingUniverse — History of GT Interactive Software
- TechRaptor — Carmack's lawsuit against ZeniMax reveals the terms of the 2009 deal
- The Digital Antiquarian — "The Shareware Scene, Part 5: Narratives of Doom"
- Wikipedia — Id Software
- Wikipedia — Doom (1993 video game))
- Wikipedia — Catacomb 3-D
- Wikipedia — Hovertank One
- Wikipedia — Doom modding
- Wikipedia — Development of Doom
- Wikipedia — John Romero
- Wikipedia — Ion Storm / Daikatana
- Wikipedia — GoldSrc
- Wikipedia — Id Tech / Raven Software
Secondary (context, cross-checking, accessed through search snippets; a direct fetch returned 403):
- GameSpot, "ZeniMax raised $105 million to buy id" (2009)
- DoomWiki.org — Doom Bible, Doom source code (the GT Interactive data were replaced with FundingUniverse, see above)
- PC Gamer — "The history of the first-person shooter"