Vanda Engine is the new FREE development platform for Games and realtime interactive 3D on Windows.
Featuring a technology called VScenes, the engine allows anyone to begin building by constructing over many layers or as we call VScenes. Technically, a VScene is a collection of objects, external scenes in COLLADA format, a PhysX XML scene or built in physics elements, rendering effects, extra textures and other such elements that form the blocks of a real time interative scene.
Accepts bitcoin donations.
site link: http://vandaengine.com/