In August of this year, a court sided with a small Canadian company called i4i that holds a 1998 patent on the way the XML language is implemented, finding that Microsoft was in violation of that patent. The result: Microsoft was told to license the code in question from i4i or reprogram it, or else Microsoft Word would have to be removed from sale in the market.
http://tech.yahoo.com/blogs/null/158160
http://tech.yahoo.com/blogs/null/158160