GemRB is a portable open-source implementation of the Infinity Engine
Orx: Data-Driven Game Engine
A fun realistic multiplayer free-and-open-source first-person-shooter!
DOOM / Heretic / Hexen source port with enhanced graphics and UI
Portable game engine with main focus on point-and-click adventures
lightweight multi platform game engine
scriptable game engine with built-in support for 2D graphics and sound
NextGen Cheat Device
Multi-platform game engine similar to old Megaman with a stage editor
plugin-based RPG manager in C++ and Qt5
Paintown is a 2d fighting game engine.
A traditional top-down OpenGL car racing game
A generic 2D engine for any kind of game
Short maths subtraction puzzle game For intelligent mathematicians.
Point-and-click 2D game engine