GLC_Player - GLC_Player Home Page
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
open3mod - A free, Open-Source 3D Viewer designed to make it all easier. Massive 3D Format support
FreeCAD - An open-source parametric 3D modeler
AccuTrans 3d - AccuTrans 3D provides accurate translation of 3D geometry between the file formats used by many...
Onshape - Onshape is the first full-cloud 3D CAD system. It runs in a web browser and on any mobile device.