If you define interoperation as something like the capability to service non-Windows OS calls on a Windows platform, then you are correct, MS has no interoperation strategy. But, what is the business justification for creating this capability when SOAP & XML allow cross platform provision and consumption of services?

As has been pointed out elsewhere, SOAP is a generic interface that allows processes to be invoked irrespective of the providers implementation technology. In much the same way, XML allows data to be transferred between systems with dispirit technologies.

"IBM puts out their own JRE and JDKs."

IBM's Java is licensed from whom?


"Sun wants no competition from other vendors for the Java franchise.

And how much competition does Microsoft brook for the Windows franchise?"

None, which is exactly my point. IT vendors don't congregate so they can sing the Barney theme song. They all want you to use their technology exclusively.