As I revealed in last week's WinInfo Short Takes, Microsoft's upcoming Office 12 suite of productivity applications will be switching to a new document format. Specifically, the versions of Microsoft Office Excel, PowerPoint, and Word in Office 12 will use an XML-based document format by default. It's hard to overstate what an important move this is for the software giant: Microsoft's critics have long alleged that the company's lock on its proprietary Office document formats was one of its chief competitive advantages.

Microsoft will reveal more information about the new format next week at Microsoft TechEd 2005 in Orlando, Florida. Dubbed the Microsoft Office XML Open Formats, the new format follows on the heels of XML support to varying degrees in three earlier Microsoft Office versions--Office 2003, Office XP, and Office 2000. "The new Office 12 XML Open Formats introduce significantly enhanced XML formats for Word and Excel, and the first XML format for Microsoft PowerPoint," said Steven Sinofsky, senior vice president of Office. "The formats use consistent, application-specific XML markup and are completely based on XML and use industry-standard ZIP compression technology."

The switch to XML-based formats means that Office 12 documents will be as much as 75 percent smaller than earlier Office document types, more reliable, more interoperable, and extensible. And Office 2003, Office 2000, and Office XP users will be able to download a small software update that lets those Office versions work with Office 12 documents. Existing Office documents will work fine with Office 12 applications.

Fans of open systems, rejoice: Microsoft will provide the Office 12 XML Open Formats as an "open, published document format" with a royalty-free license. That means that anyone, including competitors such as OpenOffice.org and Sun Microsystems StarOffice, can use the document formats without paying Microsoft for the rights. Microsoft says that this new openness will lead to wider use for the formats and better interoperability with competing solutions.

Microsoft states that Office 12 is set for a late 2006 release. That timetable coincides with the Office 12 schedule I published on the SuperSite for Windows in March and is concurrent with the expected public release of Longhorn, the next major Windows version.

Microsoft notes that Office 12 is set for a late 2006 release. That timetable coincides with the Office 12 schedule I first published on the SuperSite for Windows in March, and is concurrent with the expected public release of Longhorn, the next major Windows version.