OpenBIM & Rhino
Why didn't I know about this http://grasshopperdocs.com/addons/geomgym-ifc.html ?
"OpenBIM addon for Rhino and Grasshopper enabling IFC (Industry Foundation Class) model to be generated and exchanged to ArchiCAD, Revit, Bently, Tekla and any other BIM software with IFC capability. https://technical.geometrygym.com/getting-started/installation"
It's not Free Software, but bringing more openbim to proprietary software is part of what we're about there.
@geometrygym I've added that here: https://wiki.osarch.org/index.php?title=Free_software_extensions_to_proprietary_software#Proprietary_software_and_OpenBIM - feel free to pad out the text a bit or make a page pointing to some more documentation