BIM GeomGym IFC is an OpenBIM add-on for Rhino and Grasshopper. It enables IFC (Industry Foundation Class) models to be generated and exchanged to ArchiCAD, Revit, Bently, Tekla, and any other BIM software with IFC capability.
BullAnt is a Rhino/Grasshopper plug-in primarily for architects and engineers (but also other Rhino/Grasshopper users). It features computational design tools to enhance and extend the parent program and other third party plug-ins. BullAnt commands include mesh relaxation (minimal surfaces), mesh inflation (ETFE cushions), symmetry automation, tessellation (polygon packing), structural modeling/sketching (including parametric generation in Grasshopper), geodesic domes, and curve network processing.