On Mon 05-Apr-2004 at 05:23:40PM -0600, Eric Wilhelm wrote: > > 2. Edit model. Each change is committed to the local svn > repository (e.g. adding a line creates revision 2, adding a > circle creates revision 3, moving both of them creates revision > 4...) Now we have total undo control all the way back to when we > checked-out the model. ..or let the CAD tool keep a local journal of changes. With a diff-able CAD format, this could be a directory where the application drops a date-stamped patch file for every change. This undo list could be infinite, it would allow sophisticated operations: "undo all changes made to red circles before lunch". -- Bruno