On Tuesday, a Texas U.S. District Court issued an injunction against Microsoft, saying it couldn't sell versions of Microsoft Word that "have the capability of opening a .XML, .DOCX, . or .DOCM file (an 'XML file') containing custom XML." This would seem to stop Microsoft from selling Word 2003, Word 2007, and the forthcoming Word 2010 product. Microsoft has 60 days to appeal, and it may overturn this verdict, but it does give an IT manager pause.
So what's this all about? When Microsoft designed its XML file formats (OOXML), it included the ability to create custom schemas, somewhat akin to views in a database. The idea was that enterprises could add structured data to documents (e.g., an hCard [address] entry) without changing the underlying document schema. These custom schemas were not embedded in the document proper, but did travel along in the document .ZIP file. This meant that a document could contain multiple custom schemas: one highlighting people's names in a document, another highlighting place names, for example. This "to the side" mapping mechanism is apparently what violates i4i's patent.
ODF 1.1, the other current XML document standard, does not have such a rich custom schema mechanism, but the forthcoming ODF 1.2 standard will have a much better one. When a reporter, Kurt Mackie, called me Wednesday evening, I mused that ODF 1.2 might violate the i4i patent as well. The article reads, "The current version, ODF 1.1, doesn't use this custom XML approach, but 'ODF 1.2 will move to a similar custom schema that OOXML has, he [Guy Creese] said in a phone interview." While the quote is accurate, at this point I think I was wrong. True, ODF 1.2 supports a much richer metadata mechanism, but it's not custom XML-based, but rather RDF-based (see http://marketing.openoffice.org/ooocon2008/programme/friday_1475.pdf). The effect is somewhat the same, but the mechanism is different, and that makes all the difference, at least when it comes to patents.
How will this all play out? I'm not sure--and my impression is no one knows for sure.