UCI chess engine
Godot is a powerful cross-platform game engine
Sunfish: a Python Chess Engine in 111 lines of code
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
Multi-platform 2D and 3D game engine
Xash3D FWGS engine
Unicorn CPU emulator framework (ARM, AArch64, M68K, Mips, Sparc
Cocos simplifies game creation and distribution with Cocos Creator
A JavaScript engine optimized for running React Native
Solar2D Game Engine main repository (ex Corona SDK)
Open source voxel game engine with support for survival and crafting
A modern cross-platform low-level graphics library
Open source routing engine for OpenStreetMap
An unofficial rules engine for the world's greatest card game
A promising chess program
Chess training program playing gambits
Embed web technologies in applications
Satisfying monster shooter
Voxel game-creation platform with easy modding and game creation
Open QR Code is an open-source, cross-platform app
Tool to build cross-platform and high-performance awesome apps
Real-time physically based rendering engine for Android, iOS, and more
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
JUCE is an open-source cross-platform C++ application framework
Innovative user interfaces made easy