Nice, thanks for sharing this!

Looks like the commercial game Planet X3 is now open source (GPLv2) as well:
https://github.com/planet-x3/px3_ose

Here's a really obscure game that went open source. It's was originally called Super Pooh, an unlicensed DOS action platform game based on Winnie the Pooh characters (but with a few twists, being mostly inspired by the Soviet version).

It was sold commercially in the 90s, then the author was able to negotiate an international release on consoles, but all Pooh references had to be removed for copyright reasons, so the game became Super Plusha. Actual gameplay and levels remained the same.

The DOS game was rediscovered by enthusiasts in 2010, and the author was happy to provide the full version and the source code. Based on this, an updated DOS version and a Windows port was created by CTPAX-CHEATER, which is available here along with an interview with the author (all in Russian though):
https://ctpax-cheater.losthost.org/htmldocs/pooh.htm

The source code is released under the Apache 2.0 license and available here:
https://github.com/D0NM/Vinnie

The author gave full permission to do anything with the game data.

I happened to find this WP article yesterday, and it might have some games mentioned that aren't on this thread.... though the way WP works, that article is more likely to be updated from this thread.

https://en.wikipedia.org/wiki/List_of_commerc … ?useskin=vector

progman.exe wrote on 2024-03-10, 15:42:

https://en.wikipedia.org/wiki/List_of_commerc … ?useskin=vector

I certainly went through that list a while ago. I can't be certain I didn't miss anything, but most of the commercial DOS games with available source code are either very well known, or completely obscure and not listed there at all.

I just realised that several of the older games by Johan Peitz (Free Lunch Design) have their source code available from here:
http://www.dtek.chalmers.se/~d98peitz/fld/download.shtml

Another DOS game with the source code possibly lost: G-Fighter by Gaping Wolf Software. I was able to find the game itself here: gfighter.zip. The game was created using Allegro, but not archived at allegro.cc.

An older page of the same developer is available here:
https://web.archive.org/web/20000914170407/ht … /~rhanvark/gws/

I just learned about a pretty obscure German game called Space in Motion: Future Trade which was made freeware by its author, and the source code released here:
https://github.com/Burkersroda/FutureTrade

According to that page, the game was released in 2000 and sold in stores (here's a couple of photos of the box: amazon.de). And here's the page on the publisher's website: http://www.kellymedia.de/shop/60116.html (Wayback Machine link).

The shareware chess programme Rival Chess had its source code released to the public at some point in or after 1998:
http://www.redhotpawn.com/rival/download/download.php

MrFlibble wrote on 2024-05-05, 13:57:

The shareware chess programme Rival Chess had its source code released to the public at some point in or after 1998:
http://www.redhotpawn.com/rival/download/download.php

that web address.... 😀

these websites, their look, the screenshots - always takes me back to those early on line days and the excitement of finding a game to download

Here's another open source game made with Allegro: Gravity Force. Apparently, it's a remake of an Amiga game of the same name.

An incredibly obscure game by a certain Paul Rahme, originally released in 1995 and now available for free with the source code:
https://github.com/paulrahme/exobius

The game was written in Modula-2, which is a language I've never heard before.

It's a rather primitive shooter with a faux 3D perspective and view from behind. I'd rather expect something like this to come out in the late 80s and not in '95.

It looks like Little Big Adventure (a.k.a. Relentless: Twinsen's Adventure) and its sequel have their source code released under GPL:
https://github.com/2point21/lba1-classic
https://github.com/2point21/lba2-classic

Both repos have been uploaded 3 years ago, somehow I missed this.

JTris, a decent Tetris clone with modtracker music written in C++ with Allegro (Wayback Machine):
http://guan.is-a-geek.com/jtris/jtris.html

Something highly obscure I had on an old shareware disk, and looked up..
https://www.mobygames.com/game/60959/lumpies-of-lotis-iv/

But have not found source yet, it came as an executable on my disk, so not sure if there's a listing or a basic file around somewhere to be found.

The source code of the Mac version of System Shock was released under GPL by Nightdive Studios a while ago:
https://github.com/NightDive-Studio/shockmac

Here's another GPL cross-platform game that started as a DOS programme: Berušky. It's a neat maze/puzzle game with heavy Soko-Ban leanings, but a lot of original mechanics. I think I've seen it in some Linux distros before.