Thanks for the good analysis, Lars One thing is quite interesting: If you browse through the many new open-source CAD projects, specially the opencascade-based ones, many names appearing among developers and people hanging on forums are well-known to this list and other typical architecture/engineering/linux/opensource/cad places, and I have the impression everyone always has an eye on the neighbours. And those apps rely much on and share many different libraries, one for rendering, one for modeling, one for contraint solving, etc... and opencascade itself allows a very high compatibility between all apps (basically, same brep-based format). All this can make a good glue between all those projects. About terrible state of 2D and users being disappointed about not behaving like Autocad, I agree, it's happening already :) I fear only us architects really need 2D, which represent a very small portion of the opensource CAD bath... Yorik