Desktop/Android/HTML5/iOS Java game development framework
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
2D game development library for Ruby and C++
Cross-Platform C++ 2D/3D game engine
The Open Toolkit library is a fast, low-level C# wrapper for OpenGL
3D Procedural Game Engine Using OpenGL
Gideros Release version
A cross-platform port of Hexen II game.
A modern, cross-platform Quake game engine based on FitzQuake.
3D Engine c++
0 A.D. is a free, open-source, cross-platform real-time strategy game.
GemRB is a portable open-source implementation of the Infinity Engine
WW2 U-boat simulation
Hardcore 3D space shooter with spaceship upgrade possibilities.
GLScene Engine for Delphi & C++Builder VCL Windows 32/64
Combat Flight Simulator for LINUX. WW2. Network and VOIP. Open-source.
3D modeler, 3D game maker, 3D demo maker
Game engine supporting many 3D/2D formats and graphic effects
LDraw™ editor for LEGO® style digital building instructions.