CryEngine is a game engine developed by Crytek. The CryEngine featuring realistic features such as soft shadows, time of day, color shading, DX11 tessellation technology etc.
CryEngine 3 SDKEdit
The CryEngine 3 SDK is a level editor for game developers. Originally called Sandbox Editor. (unfinished, please add more texts, do not copy texts from Wikipedia.)
Due to it's realistic environment, CryEngine consumes much PC power even on high-end systems.