Blender - Blender is the open source, cross platform suite of tools for 3D creation.
MadMapper - The Mapping Software
FreeCAD - An open-source parametric 3D modeler
Resolume - Resolume is an application for live video performances.
Sculptris - Sculptris: Enter a world of digital art without barriers.
QLab - QLab, Live show control for Mac OS X.