My first introduction to CAD using " Computervision" software followed by "Prime Medusa" and finally Autocad 12. Progecad provides all facilities required for 3D modelling along with some features which assist very well when associating with projects where Solidworks is involved and more recently when exporting to STL files for 3D printing. Finally, I am completely satisfied with Progecad and unlikely to revert back to Autocad