The game engine for everyone
Multi-platform Engine for Desktop, XBOX (UWP) and Mobile games
New Godot bindings for Swift
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Open source library for creative expression on the web, desktop, etc.
A completely free, open-source, 2D game engine
GemRB is a portable open-source implementation of the Infinity Engine
Game engine supporting many 3D/2D formats and graphic effects
Urho3D Game engine
Engo is an open-source 2D game engine written in Go
2D Game Engine
A cross-platform 2D game engine
Portable game engine with main focus on point-and-click adventures
Paintown is a 2d fighting game engine.
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3