Fast and lightweight JavaScript game engine built on WebGL and glTF
Open game and rendering engine packed into a JavaScript framework
Game engine supporting many 3D/2D formats and graphic effects
Vivid3D is an open-source 3D engine with powerful 2D UI.
Modern 3D engine and IDE written using C# and C++.
Source code of the chapters of the book 3D Game Development with LWJGL
3D .NET engine for Windows, Linux, Mac
Open-source, cross-platform, C++ game engine for creating 2D/3D games
Mahasona engine is an open source game engine.
Cross platform 2D/3D game engine written in C++11 & OpenGL ES 2/3
XNA based game engine completely written in c#
3D Game engine
Pear3DEngine is a modern and modular 3D development framework
Delphi-like IDE for cross-platform game development
The Lambda-Engine is a cross platform game engine.