This makes me both very happy and very sad - happy because it's a brilliant thing, sad because it's in a proprietary format that requires expensive closed software to open and edit.
If you can suggest an alternative open-source CAD package, not just file format, I'd be happy to look into it. Thanks for the interest!
Providing the STEP and STL files should cover pretty much what the open source CAD world is prepared to handle - FreeCAD can import STEP and BRL-CAD is working on it, and most 3D printing applications I know of can work with STL just fine. Thank you for taking the trouble to make the extra formats available.