The flexible game engine
An iOS & tvOS Frontend for Multiple Emulators
Naev is a 2d action/rpg space game, action, rpg and simulation
3D game engine/framework in C, with Luajit and Python bindings now
A cross-platform, open-source, pure C game engine for mobile game
Game engine to build text adventures.
Orx: Portable Game Engine
Retro game engine for creating games like it's 1997
A modern, cross-platform Quake game engine based on FitzQuake.
A cross-platform port of Hexen II game.
Updated emulator of Forgotten Realms: Unlimited Adventures
A free 3d game for PC that does not limit the player. Fight,Build,Gain
Open source FPS/RTS Game
A 16 bit style game on the 16-bit IBM XT.
SDL based generic 2D game engine
0 A.D. is a free, open-source, cross-platform real-time strategy game.
a UCI chess engine
DOOM / Heretic / Hexen source port with enhanced graphics and UI