Just For Future Reference …
I heard somebody say (an official at a government-sponsored workshop)
… interoperability doesn’t mean that everyone has the same radio ….
Classic. We already know that interoperability is in designing our radio systems to work together, no matter who made them. There are even government grants that are given to local safety agencies to help them build that capacity into their systems.
So tell me again how OOXML is designed for interoperability. Is it designed with the needs of any other software vendor's products in mind? Does it abstract away enough details of the in-memory representations to enable competing implementations to be just as capable? Are the "IP" conditions workable for producers of competing and alternate implementations of office-type functionality?