Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Gmsh - Gmsh is a 3D finite element grid generator with a build-in CAD engine and post-processor.
Sculptris - Sculptris: Enter a world of digital art without barriers.
TetGen - A Quality Tetrahedral Mesh Generator and a 3D Delaunay Triangulator
ZBrush - ZBrush is a digital sculpting and painting software solution.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.