Microsoft's US XML Patent Application
Groklaw, publication date: 15 March 2005
"Here it is, ladies and gentlemen. Step right up. It's Microsoft's United States Patent Application #20040210818 and it was filed originally in June of 2002 and listed on October 21, 2004. The abstract reads like this:
Word-processing document stored in a single XML file that may be manipulated by applications that understand XML"