First post, by MrFlibble
Being generally interested in open source software, I started to wonder how many DOS games were or became open source. There are of course those well-known releases like Doom, however many other games also went open source (and some were open source from the start). Having found no list specifically dealing with DOS games (with additional confusion coming from people who for some reason treat the terms "open source", "public domain" and "freeware" as synonyms), I decided to try and list those that I know or could find information about.
The games on the list are freeware unless noted otherwise. Also the fact that a game is open source doesn't mean there is a DOS executable compiled from the source that is available for download.
Beyond the Titanic
Beneath a Steel Sky
Blake Stone: Planet Strike [commercial]
Clonk 2 Debackel
Clonk 3 Radical
Descent II [commercial]
Duke Nukem 3D [shareware]
HeXen: Beyond Heretic [commercial]
In Pursuit of Greed
Jump 'n Bump
Linley's Dungeon Crawl
Mike's Adventure Game (MAG)
Rise of the Triad [shareware]
Shadow Warrior [shareware] [Steam free version]
Stellar Conquest III
Wolfenstein 3-D [shareware]
*Originally not a DOS game.
** The publicly available version of the source code is a translation of the original code from TurboPascal to C.
There's also a fair deal of open source games listed here, some of which are for DOS but at present I can't be bothered to investigate.
I'm pretty certain that there are more open source DOS games out there, and probably not only some obscure titles but also more or less well known ones, which I missed. Anyway, if someone knows more games that should be on this list, please tell! 😀