It is no accident that many of the early applications for Linux were emulators, APIs and virtual machines for the older home computers, so users could play the games they had known on DOS, the Sinclair QL, Amiga or the Commodore 64.
While at University in Aberystwyth, Alan Cox co-authored a game called AberMUD, said to be the first popular open source MUD or Multi-User Dungeon game, originally written in B, the programming language derived from BCPL which Ken Thompson had used to write the first versions of Unix, and afterwards ported to C.
Cox went on to work for a brief time in the games industry, and later reminisced that it was run "by the people who failed to get into the music industry because they'd have to think a moment before selling their grandmother."
"Like the music industry nobody in the computer game industry made any money," Cox remembered, "but mysteriously all the game company owners drove expensive cars and lived in huge houses."
"The whole Linux thing was really an accident," he told KernelTrap in 2002. "My interest was text based adventure games (the world of Colossal Cave, etc.) and also multi-user games based on that style (Essex MUD1 and so on). I got into Linux looking for a better platform to develop AberMUD on."
Linux gives me a woody
Gaming shares many roots with open source, and many games coders would see themselves in a similar light to free software coders – as creative hackers exploring the cutting edge of computing. A game may not have any useful function other than the game itself, but computers are only as good as the last game you played. And each new game asks a little bit more of the code, the graphics, and the chips that run the machine.
According to the Linux DOOM README file, when David Taylor of id Software was asked why he decided to port DOOM to Linux in 1994, he responded: "I did this 'cause Linux gives me a woody. It doesn't generate revenue."
Just as remarkably, id Software open sourced Wolfenstein 3D in 1995 and DOOM in 1997, taking the attitude that "we've sold as many as we're going to sell, and giving out the code is cool", and might just encourage innovation and collaboration.
DOOM was notable for being the first mainstream computer game that came with a Linux binary, and id Software has ported many of its major titles to Linux, on a similar basis to Taylor's original port of DOOM – even though as John D. Carmack, one of id Software's founders, said back in December 2000, "it doesn't look like a strong business case can be made for it. The Mac version outsold the Linux version by quite a bit, and even that didn't hit 5 per cent of the Windows sales. Mac versions are still valid business cases, because the support is way easier than on either Windows or Linux platforms, and the sales numbers amount to something noticeable."
Carmack has also contributed to open source projects, and is a notable opponent of software patents, of which he has said: "Yes, it is a legal tool that may help you against your competitors, but I'll have no part of it. It's basically mugging someone."
The first Linux games company
The first dedicated Linux games company was Loki, named after the Norse god of mischief. Loki was founded by an ex-lawyer Scott Draeker in November 1998, with the objective of porting popular games to Linux, which it did with some plaudits and success; it brought 19 games to Linux, including ports of Civilisation: Call to Power, Alpha Centauri and Quake. Loki also employed quite a few programmers who went on to become well known figures in Linux and gaming, but was the victim of careless management and lack of planning, and went bankrupt in August 2001.
Loki may have been one of those companies that was ahead of its time, and may have tried to run before it could walk, but left a notable legacy in the shape of open source libraries and tools that remain central to the Linux gaming infrastructure. These include the Loki installer, the Simple DirectMedia Layer (SDL), which enables interaction between the joystick and the screen, OpenAL 3D audio, and GtkRadiant.
Other games companies that have followed the lead of id Software in open sourcing all or part of their games have included Epic, that has open sourced parts of the engine for Unreal Tournament, and Linden Lab, the maker of Second Life, that has released Second Life under the GPL to encourage participation, and sees open source as a positive opportunity to widen the possibilities of the game beyond its original scope.
Others have released the source code on the same basis as id Software, that "we've sold as many as we're going to sell, and giving out the code is cool", which is good as far as it goes. But as yet, no commercial games company of any size has dared to be the first open source game company, and develop a game that is GPL'd from scratch.