Microsoft still denies that it will support the increasingly-important OpenDocument format in its upcoming office productivity suite, currently codenamed Office 12. But the company revealed late last week that it will allow Office 12 applications to save in XML Paper Specification (XPS) format, an XML-based document format that was previously codenamed Metro and is designed for paper-based output only.

It's unclear why this is big news. Microsoft, after all, is the inventor of the XPS format, which many analysts see as a threat to Adobe and its popular PDF format. "This Office feature provides a one-way export from Office client applications to an application- and platform-independent, paginated format," Jeff Bell, an Office program manager, revealed in his blog last week. Bell says that Microsoft will ship viewer applications for XPS, allowing users without Office 12 to view and print XPS documents (this functionality will be built into Windows Vista, presumably).

However, in addition to its support of XPS, Office 12 will also support saving to PDF format. Competing office productivity suites from Corel, OpenOffice.org, and Sun Microsystems have supported this functionality for years. And Apple includes native PDF integration in its Mac OS X operating system; any application running on OS X can therefore save documents to PDF format using the Print function.

XPS and PDF will be treated as Export options in Office 12, and not as full-fledged document formats that support "round-tripping," where different users edit the same document in different formats. By comparison, native Microsoft Office document types (.doc and .xls, for example) and the new Open XML document formats that Microsoft is using in Office 12 will support round-tripping. OpenDocument, utilized by the recently-released OpenOffice.org 2.0 and Sun StarOffice 8 office productivity suites, also supports this functionality. OpenDocument is being adopted by a variety of government agencies around the world. The US state of Massachusetts is currently switching all of its official documentation to that format.

To date, Microsoft has refused to support OpenDocument, and denied recent reports that it was examining that possibility. "We have no plans to directly support the OpenDocument format at this time," the company wrote in a statement issued last week. "Our standards-based formats for Office 2003, as well as our announcement that XML will be the default file format in Office 12, have been extremely well received by customers and partners ... We fully expect partners, independent companies, and competitors to provide converters between our Open XML formats and the OpenDocument formats, and are aware of a few projects along these lines already."