LeoCAD - LeoCAD is a CAD program for creating virtual LEGO models.
open3mod - A free, Open-Source 3D Viewer designed to make it all easier. Massive 3D Format support
LDraw - LDraw is an open standard for LEGO CAD programs that allow the user to create virtual LEGO models...
Autodesk FBX Review - FBX Review is a lightweight, standalone software tool for viewing 3D assets and baked animations...
Stud.io - Build LEGO designs online with friends.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.