I wasn’t aware of this and thought it was cool.
From The Robustness Principle Reconsidered:
The original InterOp conference was intended to allow vendors with Network File System (NFS) implementations to test interoperability and ultimately demonstrate publicly that they could interoperate. The first 11 days were limited to a small number of engineers so they could get together in one room and actually make their stuff work together. When they walked into the room, the vendors worked mostly against only their own systems and possibly Sun’s (since as the original developer of NFS, Sun had the reference implementation at the time). Long nights were devoted to battles over ambiguities in the specification. At the end of those 11 days the doors were thrown open to customers, at which point most (but not all) of the systems worked against every other system. By the end of that session the NFS protocol was much better understood, many bugs had been fixed, and the standard was improved. This is an inevitable path for implementation-driven standards.