The definition of openBIM could be: Real interoperability by using of open technology.
The idea of interoperability is to focus on the process and how well the various BIM Tools operate together instead of the features of one single tool. More then 35 software vendors with in total more then 50 applications nowdays adopting openBIM trough IFC (Industry Foundation Classes). Another example of this is the BIM Collaboration Format.
BIM Collaboration Format allows project partners to communicate information linked to specific objects in the buildingSMART Model (IFC). A number of popular software supports the BCF standard, including Tekla, Solibri, DDS-CAD and others. Issues will be linked to the objects in the model (using GUIDS) and can be communicated through all project partners. The "camera" position used when saving a screen shot will also be saved together with the issue and remarks. When opening a BCFzip file in any other BCF compliant application, you can zoom in to exactly the same view. This increases the process and information flow. The BCF issues can be created manually or from clash detection software and other analysis tools. BCFzip files can be also dragged and dropped directly into the dialogue box in the compliant software application. Another function with BCFzip files is to merge several BCF files.
openBIM = open process and therfore open information
The endpoint will be the "level of openBIM (LOOB)" simular to "level of detail (LOD)"
IFC2x4 –the next step to openBIM