Blender - Blender is the open source, cross platform suite of tools for 3D creation.
ZBrush - ZBrush is a digital sculpting and painting software solution.
MilkShape 3D - The MilkShape 3D website has been down for almost one week.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
SelfCAD - SelfCAD is an online 3D modeling and slicing software.
Metasequoia - Metasequoia is suitable for beginners, and for professional of 3D modeling and for users using other 3DCG professional software or 3D printer.