Open source clone of the Age of Empires II engine
A free 3D game engine to create games and realtimes scenes for Windows
DOOM / Heretic / Hexen source port with enhanced graphics and UI
A fast, scalable, distributed game server engine/framework for C++
Game engine for playing tomb raider 1 - 5 levels.
2D game engine for traditional platform games
A C++ 3D game engine.
Mahasona engine is an open source game engine.
Open Source 3D Game Engine
A 2D Adventure Game & Engine
TurboSphere is an easy to learn and powerful JS based game engine.
BxEngine For Marmalade And QT
A retro style video game engine for RPGs and adventure games.
Open source, moddable game engine for the "Polygon Love 2" game
WGFX 2D Game Engine
Point-and-click 2D game engine
Cross-platform 2D game engine