Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
MakeHuman - MakeHuman is a free, open source, interactive modeling tool for creating custom 3D human characters.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
Bforartists - Bforartists is a fork of Blender.
Sculptris - Sculptris: Enter a world of digital art without barriers.