Edwards said his plug-in can already save Word documents in OpenDocument while retaining formatting and other metadata. More work is needed, however, to make Excel and PowerPoint save files properly in OpenDocument, he said.

Edwards was formerly OpenOffice.org's technical liasion to the Organization for the Advancement of Structured Information Standards (OASIS), the consortium that fought to turn OpenDocument into a standard. But that pedigree hasn't made Edwards immune from criticism by OpenOffice advocates.

"I understand that Massachusetts is under the gun to migrate and that this might make it easier to fulfill their mandate," said Louis Suarez-Potts, community manager for OpenOffice.org. But in general, "I see anything that extends the life of Microsoft Office as problematic."

Edwards conceded that a side effect of his and other possible plug-ins could be to slow the adoption of OpenOffice. "Yes, I want to see OpenOffice on every desktop," he said. "But I think in many ways you are right to say that, yes, we are extending the usefulness of Microsoft Office."

Partly as a concession to his open-source critics, Edwards said he is not now working on making the plug-in work with Office 2007. But he acknowledged that if Massachusetts was interested enough in Office 2007 compatibility to pay for it, he would be hard-pressed to refuse to build it.