A cross-platform PSP emulator
SDL library for Android, including several games.
Desktop/Android/HTML5/iOS Java game development framework
A certain block game
Voxel game-creation platform with easy modding and game creation
UCI chess engine
Stream switch games to your PC via USB or network
Home theater software and entertainment hub for digital media
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
The game engine for everyone
Solar2D Game Engine main repository (ex Corona SDK)
Open-source engine for Heroes of Might and Magic III
Multi-platform 2D and 3D game engine
Cocos simplifies game creation and distribution with Cocos Creator
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Android, UIQ 3.0, Series 60 Edition 5 open-source software
3D Engine c++
3D modeler, 3D game maker, 3D demo maker
GemRB is a portable open-source implementation of the Infinity Engine
... the open-source glide computer
GLScene Engine for Delphi & C++Builder VCL Windows 32/64
computer opponent for the board game Blokus
0 A.D. is a free, open-source, cross-platform real-time strategy game.
Old style soccer game with many exciting features