Welcome to the world of surprising patent lawsuits. A Texas judge ruled Tuesday that Microsoft cannot sell Word - yes, Microsoft Word, the cornerstone of Microsoft Office - in the United States.

Toronto-based i4i Inc won an injunction against Microsoft regarding the company's XML patents. In the words of i4i, the injunction "prohibits Microsoft from selling or importing to the United States any Microsoft Word products that have the capability of opening .XML, .DOCX or DOCM files (XML files) containing custom XML". Microsoft has been given 60 days to comply, reports Seattle PI.

The injunction reads:

Microsoft Corporation is hereby permanently enjoined from performing the following actions with Microsoft Word 2003, Microsoft Word 2007, and Microsoft Word products not more than colorably different from Microsoft Word 2003 or Microsoft Word 2007 (collectively “Infringing and Future Word Products”) during the term of U.S. Patent No. 5,787,449: 1. selling, offering to sell, and/or importing in or into the United States any Infringing and Future Word Products that have the capability of opening a .XML, .DOCX, or .DOCM file (“an XML file”) containing custom XML; 2. using any Infringing and Future Word Products to open an XML file containing custom XML; 3. instructing or encouraging anyone to use any Infringing and Future Word Products to open an XML file containing custom XML; 4. providing support or assistance to anyone that describes how to use any infringing and Future Word Products to open an XML file containing custom XML; and 5. testing, demonstrating, or marketing the ability of the Infringing and Future Word Products to open an XML file containing custom XML. This injunction does not apply to any of the above actions wherein the Infringing and Future Word Products open an XML file as plain text.

Needless to say, Microsoft won't pull Word off the market. The company has said it plans to appeal, and i4i actually sells XML products for Word, making that company reliant on the ecosystem. An agreement will be reached: probably one involving Microsoft signing a big check.