The project, to be hosted on Sourceforge.net, will be led by three independent software vendors (ISVs) funded by Microsoft and is open to all developers, according to Tom Robertson, general manager for standards and interoperability for Microsoft.

The goal is a free plug-in that allows users to natively save files in ODF within Office, as well as convert files in Office 2007's OpenXML format to ODF and back. That plug-in is expected by December, with similar plug-ins for Excel and PowerPoint expected in 2007, according to Jean Paoli, Microsoft's general manager for interoperability and XML architecture.

The Belgian and Danish governments both announced last month that they will move to ODF, a free XML file format approved by the International Organization for Standardization (ISO) in May. They join Massachusetts, which said in September it would begin migrating state employees to ODF by Jan. 1, 2007.

Norway and France are also considering ODF, which proponents argue is better at ensuring long-term accessibility to documents and opens the door for organizations to use alternative productivity software, including OpenOffice.org and Sun Microsystems Inc.'s StarOffice.

"XML is good, standardized XML is good and choice is good. This is an interesting announcement," said Louis Gutierrez, CIO for Massachusetts. Gutierrez, who took over at the beginning of the year, told Computerworld earlier this year that he had suggested to Microsoft that they create a plug-in that would translate between OpenXML -- the native file format of Office 2007 -- and ODF.