CryEngine

CryEngine is an commercial open-source game engine designed and developed by the German game developer Crytek. With CryEngine, game creators can achieve their goals faster by building games on an already proven game engine that provides its full source code. The engine is provided with no up-front cost, only a royalty percentage of 5% of the gross receipt, which makes it perfect for game developers and teams with a low budget or funding. Surrounding the project is a large community and a market place filled with user-made game assets that can be used to increase the speed-to-market.