While responding to an earlier comment, I came across a nice write-up from Mike Gunderloy of Microsoft's recent decision to license the XML schemas used by Office 2003 apps.  There was a lot of news coverage when the Office team filed patents to cover these file formats, but they did establish a program to license out the schemas, royalty-free, regardless of patent status.

Mike raises some issues with some terms of the license, but this is certainly a significant shift from the policy on the .doc and .xls file formats.

Has anyone made use of these schemas and the licensing program thus far?