FreeCAD is an OpenSource CAD/CAE, based on OpenCasCade, QT and Python.

It features some key concepts like macro recording, workbenches, ability to run
as a server and dynamically loadable application extensions and it is designed
to be platform independent.

Warning: FreeCAD is still in ALPHA state and not in shape for end user usage!

WWW: http://juergen-riegel.net/FreeCAD/Docu/