As a teenager I reached out to the authors of RoboWar and asked if I could have the source code to help port it to Mac OS X. A trifling detail I omitted was that I had no clue how to write C, whoops. How hard could it possibly be?
I also received the sources to Despair from Lloyd Burchill, which I was similarly unequipped to port. But unfortunately I didn't upload it anywhere.
There's also the game engine World Builder by Bill Appleton (of SuperCard fame), which Alexei Svitkine re-implemented in Java at https://github.com/asvitkine/wage-engine. This was used by several puzzle-adventure games. One I remember fondly is A Mess of Trouble by Ray Dunakin, which has been separately ported to modern macOS at http://www.amessotrouble.com/.
There's also an open source implementation of the Riven game engine for modern macOS, https://github.com/jfroy/rivenx. Though the Myst series has since been re-released.
Nonetheless, I got it on SourceForge and it seems a later maintainer ported it to Windows. https://sourceforge.net/projects/robowar/files/Original%20Ro...
I also received the sources to Despair from Lloyd Burchill, which I was similarly unequipped to port. But unfortunately I didn't upload it anywhere.
There's also the game engine World Builder by Bill Appleton (of SuperCard fame), which Alexei Svitkine re-implemented in Java at https://github.com/asvitkine/wage-engine. This was used by several puzzle-adventure games. One I remember fondly is A Mess of Trouble by Ray Dunakin, which has been separately ported to modern macOS at http://www.amessotrouble.com/.