Have been using "CAD" for many years. Started using HP ME10/ME30 on Unix workstations before PCs could really run this type of software. Used ProEngineer running on Silicon Graphics workstations in the early nineties. Used a few different Finite Element Modelling / Analysis programs in my job as a mechanical engineer and also mechanisms analysis programs too. Have used Solidworks, SolidEdge, IronCad, Archicad, Chief Architect and various other CAD type programs to varying levels of competence.