STLFinder - The 3d models search engine.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Thingiverse - Thingiverse.com is the place to share digital designs for fabricating real, physical objects.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
Cults 3D - Cults is a marketplace that connects designers and people who want to 3D print some objects.
Autodesk Maya - Maya is 3D computer animation software with powerful modeling, rendering, simulation, texturing, and animation tools for artists, modelers, and animators.