http://www.powershape-e.com/general/cad_data.asp
PowerSHAPE is a nurbs-based hybrid surface and solid modeler. It also has the ability to combine triangulated artwork, wrapped onto and trimmed into the model. Delcam call this Total modelling.
http://www.powershape-e.com/general/total_modelling.asp
A completely free version of PowerSHAPE (containing the full modelling functionality) is available - called PowerSHAPE-e.