Unity3D Client And C# Server Framework
An API for interacting with Starcraft: Brood War (1.16.1)
.NET - VISUAL BASIC NVIDIA +ATI PHYSX SLIMDX DIRECTX 9 -ENGINE/WRAPPER
3D Game engine
Modular Gaming Open Source Persistent Browser Based Game Framework
GameWizzard is a Sprite editor.
A lightweight HTML5 Game Engine
Zap Engine