Use XML to make it easier for us to read each other’s word-processing documents: pretty good idea. Too bad Microsoft now appears to own that idea:

The patent appears to cover both the creation of the XML document and the file that’s created. That would allow a certain degree of leeway in terms of interoperability, as there is nothing here that would seem to cover reading a Microsoft-generated XML document, for example. But it certainly seems that Microsoft could assert that any word processor that used this class of XML storage as a native format was violating its patents.

The key question going forward is what Microsoft chooses to do with this patent now that it has been granted. The company is under pressure in both the US and EU to increase its software’s interoperability with that of its competitors, so a rigorous enforcement of this patent would seem like an express lane to further legal trouble, something the company has seemingly been anxious to avoid [John Timmer, “Storing Text Docs in XML May Run Afoul of Microsoft Patent,”, 2009.08.07].

No word on whether Microsoft is seeking patents on RDF apps….