GemRB is a portable open-source implementation of the Infinity Engine
GameServer is a sophisticated, game server designed for online games
The AWS GameKit Plugin for Unreal
ZED OS the clone of Windows XP
Character animation system for games and simulations.
Test project with a 2D platform game developing in Godot 3.1
C/C++ , PHP, PYTHON, 3D ENGINES, CHROME NATIVE CLIENT
Make games with Lego-like building blocks