Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Pygame - Pygame is a set of Python modules designed for writing games.
Sculptris - Sculptris: Enter a world of digital art without barriers.
Unigine - Unigine Engine is a proprietary cross-platform middleware, developed by Unigine Corp.
ShapeShop - ShapeShop is an advanced and professional 3D design and modeling application that comes with an easy-to-use and user-friendly interface.
libtwo - All-purpose c++ app prototyping library, focused towards live graphical apps and games