>>
Most important is System.Xml, since those classes cannot be subclasses in .NET and therefore you cannot create COM wrappers for them to call within VFP using VS .NET.
>>

Is this entirely correct? What about a proxy/wrapper class in .NET? I understand that sealed classes cannot be inherited. I don't recall seeing the sealed property on any of these classes. IAC, it seems to me that a wrapper/proxy sceanrio could achieve substantively the same thing.