The game engine for everyone
Powerful, mature open-source cross-platform game engine for Python
Amateur 3D Game Engine
Here we're trying to create the easiest open-source game engine.
Free, open source game engine online
2D game development library for Ruby and C++
Free and Open Game Programming Language for Windows and GNU/Linux
A project to create a blazingly fast Swift game engine
A 2d physics game engine for JavaFX
Godot is a fully featured, open source, MIT licensed, game engine.
TurboSphere is an easy to learn and powerful JS based game engine.
A multiplatform game engine for interactive fiction experiences
Free MMORPG Engine. Develop and host graphical browser-based games.