+1 I too would dearly love FreeCAD to succeed because the FOSS world dearly needs at least semi-decent parametric MCAD. My view is that the UI and UNDO proble

+1 I too would dearly love FreeCAD to succeed because the FOSS world dearly needs at least semi-decent parametric MCAD. My view is that the UI and UNDO problems that you report are likely more tractable than the deeper problems with OCE. My first encounter with CASCADE was before it was Open in 1993 and Maura was still trying to sell it. I was a consultant at the time, and the client at the time was initially sold on it by the Matra salesman. At the end, though when CASCADE utterly failed to perform he had a screaming row with the Maura consultant. CASCADE was refactored from Euclid which was the loser MCAD system of the time because it didn't really support curved surfaces properly. Then Dassault purchased Matra, presumably for the Euclid client base who they swiftly moved onto CATIA, and they saw no value in the CASCADE technology so OCE was born.