OPEN BIM is a universal approach to the collaborative design, realization, and operation of buildings based on open standards and workflows. OPEN BIM is an initiative of several leading software vendors (GRAPHISOFT, Tekla, Trimble . . .) using the open buildingSMART Data Model.
The main drive behind OPEN BIM is to provide a transparent, open workflow, allowing project collaborators to participate regardless of the authoring software they use.
You can watch a short clip on ‘OPEN BIN in action’ here