Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Castle Game Engine - An open-source 3D/2D game engine for ObjectPascal.
ZBrush - ZBrush is a digital sculpting and painting software solution.
Open 3D Engine - Open 3D Engine is an open-source 3D game development engine in real-time.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
WaveEngine - The definitive free cross-platform mobile engine to unleash your games using C#.