Flowlab - Flowlab is an online game creator. Make your own games to share with friends.
Reality Factory - Reality Factory is a free suite of game development tools for building 3D games.
Wick Editor - The Internet's free and open-source creation toolkit.
Project Anarchy - Project Anarchy is a complete end to end game engine and state-of-the-art toolset for mobile.
Unity - The multiplatform game creation tools for everyone.
Wicked Engine - C++ game engine focusing on modern rendering techniques.