Game/Scene Development System
OgreWin3D
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
3D Game engine
Pear3DEngine is a modern and modular 3D development framework
Delphi-like IDE for cross-platform game development
Cross-platform 2D game engine
The Lambda-Engine is a cross platform game engine.