Undo/Redo code is progressing smoothly. It now works for creation, deletion, motion, changing item attribute. This is a really nice feature. Also I 've take care to implement a nice way to handle the undo/redo-buttons/menu item, so that other DrGeniusMDI can use the same UI mecanism. When I'll have finished that, I've decided to implement Guile scriptability for the geometric engine, GKO will eventually help on that but well... I'm quite carefull with code contributor now, I've learn a lot with Dr.Genius concerning this topic, it's difficult for people to keep sustained motivation in free software project.