based on OpenCascade:
I think this is a great effort by dan heeks. I’ve not tried it yet, but I like that he’s in to CAM/CNC as well and has written an app to output CAD models to GCode. (here). He’s also developing an “art” module, tho I’m not fully sure of what he’s doing there (link.) His blog is here.
I don’t know if he’s aware of blender and its capabilities to contribute to that stuff… I would drop him a comment, 'cept I don’t have a google account.
Any programmers looking for a project should definitely jump aboard this effort! 
It will be good if he could get involved in Blender or somehow to marry the two projects. On Blenderstorm I proposed to integrate QCad as a drafting tool (similar to Grease Pencil). maybe HeeksCAD could be that tool - similar to Grease Pencil being turned on/off in an as needed base. a
I doubt the two projects are that compatible - he’s a dotNet programmer basing his system on OpenCASCADE and xwidgets. I’d say just let him get something up that works and maybe has dumb-geometry transfer (a-la STL) between the two.
To take blender in the direction of CAD isn’t that helpful for anyone. Not that there couldn’t be more useful CAD-like functions in blender to make things like offset and 2d fillet easier. (Midpoint or intersection snap anyone? How 'bout true circles with centerpoints, quadrants and tangents? Youbetcha, I’ll take 'em!) But to look to blender to be full-functioning production-ready CAD is zany. Anyone who’s done parametric solids wouldn’t ever look back to polygon/surface/wireframe geometry if they could help it, IMO.
Don’t mean to go off here… just to say that folks here should join him and his efforts there, not necessarily the other way around.