Probably the way with the least amount of work overall would be that I'd do all the XNurbs/MOI integration work myself (because it's a lot of work to make a full C++ SDK, I can make a specialized one with just what is needed for XNurbs a lot more easily) but the resulting plug-in would be sold and distributed only by the XNurbs team as they do with Rhino and SolidWorks plug-ins currently.

That way there doesn't have to be any IP licensing set up which greatly simplifies things.

For timing probably near the start of the MOI v6 cycle would work because I'm heavily occupied with ACIS integration work for trying to wrap up v5.

Thanks, - Michael