It has been over 15 years since I took an in-depth look at the IFC (Industry Foundation Classes) open standard and my reason for doing so at that time was that with the increasing interest in BIM in the AEC community, “the issue of interoperability as a means to integrate the various model-based applications into a smooth and efficient workflow” had emerged to the forefront of professional attention. Here we are, all these years later, and the interoperability issue is still as critical as ever, if not more so. The number of applications for the AEC industry has exploded, and it is likely to continue to increase. We need all these applications to be able to work together in order for them to be able to do what they need to do — help AEC professionals design, construct, and operate buildings and infrastructure as quickly, efficiently, and cost-effectively as possible. And in order to work together, they need to be able to exchange the building data they are creating and…