Microsoft is to sponsor an open source project that aims to bring support for the Open Document Format to its Office productivity suite.

The Open XML Translator project has released an early prototype of the tool, which is governed by the open source BSD Licence and hosted on Sourceforge.net. It will support past and future versions of Microsoft's Office suite.

Microsoft is acting as a 'sponsor', leaving the main development work to partner companies including Clever Age, Aztecsoft and Dialogika, based in France, India and Germany respectively.

Given the open source nature of the project, individual developers will be able to contribute and make alterations.

"By enabling this translator, we will make choice and interoperability a more practical option for our customers," said Jean Paoli, general manager of interoperability and XML architecture at Microsoft.

"It is very important that customers have the freedom to choose from a range of technologies to meet their diverse needs."

But Microsoft is still dragging its feet, according to Simon Phipps, chief open source officer at Sun Microsystems, and a long-time supporter of the ODF format.

Although the tool allows users to import and export ODF documents in Office 2007, it will not allow users to set ODF as the default Office file format.

"Microsoft has architected this to make ODF as hard to work with as possible, " Phipps wrote on his blog.

"But it does mean that those who have to stick with Microsoft's products are able to join in with ODF-based workflows."