Its no surprise that Microsoft has been filing patent applications to protect .NET (CNET report). Now the issue is coming into the open it really does make you wonder as to what they intend to do about other implementations of .NET, such as Mono, which are covering the whole of .NET, not just the stuff in the ECMA specification.
I've just had a look at the libraries specified by the ECMA standard (available here) and although there is obviously a lot missing compared to Microsoft's .NET framework, there might be enough in it as a base class library. I don't necessarily believe that everything in Microsoft .NET should be replicated - it would be nice to see .NET open source projects breaking new ground instead of slavishly copying Microsoft - but obviously it would be bad if a load of basic library functionality had to be reproduced. From a quick look at the specified libraries its not clear to what degree this is the case. For example, the XML DOM classes seem to be missing although the XmlReader/Writer classes are there. That's a big omission but the XML DOM might be covered by W3C standards for all I know.
From a personal point of view its clear that XML-RPC.NET uses classes which are not in the ECMA standard, so I have a practical interest in knowing what the patent position is. I'd like the library to run on non-Microsoft platforms which may be restricted to the ECMA-compliant base classes. Of course other library classes which do not copy .NET but have similar functionality mght be available on these platforms, but that spoils the usefulness of a framework which is guaranteed to be available everywhere. Maybe I should factor out the functionality required for working with ASP.NET and .NET Remoting and ensure the remainder is ECMA compliant.
The patent application itself is completely confusing to my untrained eye, so broad as to be seemingly meaningless. No doubt there will be some useful analysis over the next few days to clarify this.