Netfabb - Innovative software solutions for 3D printing and additive manufacturing.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
ADA STL Viewer - FREE software for visualisation of STL or OBJ meshes
meshmixer - meshmixer is an experimental 3D modeling tool for making 3D mashups without too much hassle.
Magics - Magics rapid prototyping software enables you to import a wide variety of CAD formats and to export...
FreeCAD - An open-source parametric 3D modeler