Onuma created BIMXML Standard for describing building data (sites, buildings, floors, spaces, and equipment and their attributes) in a simplified spatial building model (extruded shapes and spaces) for BIM collaboration. More technical information can be found HERE.

The Onuma BIMXML Converter is a Java based application that imports BIM IFC files to Onuma. It runs on PC or Mac, and is available as part of Onuma.