Unity is a game development ecosystem: a powerful rendering engine fully integrated with a complete set of intuitive tools and rapid workflows to create interactive 3D and 2D content; easy multiplatform publishing; thousands of quality, ready-made assets in the Asset Store and a knowledge-sharing community.

For independent developers and studios, Unity’s democratizing ecosystem smashes the time and cost barriers to creating uniquely beautiful games. They are using Unity to build a livelihood doing what they love: creating games that hook and delight players on any platform.

Ref:http://unity3d.com

Ref:http://unity3d.com/cn/unity

Ref:http://unity3d.com/cn/learn/documentation

Unity