Here is Iron Seed, a old (commercial) Dos game of space trading and strategy,now OpenSource and ported to linux using FreePascal.
This version is not compiled with OpenGL, but it is only used for Scalling, and the game use 640x480 so nothing is lost.
Here isSDLPoP, an Open source version of Prince of Persia based on a disassembly of the DOS version.
The PND now include the data
This game use SDL2 and gl4es.
I have mapped (X) to Up (i.e. Jump) and (B) to Shift (walk), to make things easier. Also, use Ctrl-Q to Quit (ESC just toggle Pause)...