CAD Software
From PROBOTIX :: wiki
AutoDesk 123D
http://www.123dapp.com
Fusion 360
http://www.autodesk.com/products/fusion-360/overview
Google Sketchup
http://www.sketchup.com
Blender
https://www.blender.org
Moi3D
http://moi3d.com
Rhino
https://www.rhino3d.com