Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Bforartists - Bforartists is a fork of Blender.
ZBrush - ZBrush is a digital sculpting and painting software solution.
Art of Illusion - Art of Illusion is a free, open source 3D modelling and rendering studio.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
Topogun - TopoGun is a stand-alone resurfacing, and maps baking application.