Godot is a powerful cross-platform game engine
One framework for creating powerful cross-platform games
Desktop/Android/HTML5/iOS Java game development framework
A simple and easy-to-use library to enjoy videogames programming
Open source library for creative expression on the web, desktop, etc.
JavaScript framework to build game engines, games, emulators and apps
2D Game Engine
Cross-platform 2D and 3D game engine
Open-source, cross-platform, C++ game engine for creating 2D/3D games
3D .NET engine for Windows, Linux, Mac
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3
A cross-platform OpenGL based lightweight scenegraph library
Cross-platform 2D game engine
The Objective-C Interactive Simulation Abstraction Layer