http://interopvendoralliance.org/labs/

http://blogs.technet.com/photos/gray_knowlton/images/2907182/original.aspx

The Interop Vendor Alliance has been testing various scenarios with Open XML interoperability. If you're not familiar with the Interop Vendor Alliance (IVA), you can read about their activities here. They've done some interesting work in the area of identity management, system management and other things. Their testing of Open XML involves translation to ODF, use of custom-defined schema and mobility scenarios where Open XML documents are being utilized on mobile devices.