Reality Factory - Reality Factory is a free suite of game development tools for building 3D games.
Roblox - Reimagining the way people come together.
Project Anarchy - Project Anarchy is a complete end to end game engine and state-of-the-art toolset for mobile.
HiberWorld - HiberWorld is a website that allows you to make and play 3D levels for speedrunning
Wicked Engine - C++ game engine focusing on modern rendering techniques.
KoGaMa - Kogama is a Massively Multiplayer Online, Sandbox, City-Building and Adventure-based video game.