(FORTUNE Magazine) - In the early morning hours of May 3, a dramatic piece of news out of Geneva began caroming through the online world: At long last, Microsoft's lock on the $9 billion office-application business was facing a challenge.

The development? An esoteric international standards body had approved a new file standard--called OpenDocument format, or ODF--for saving office documents.

For years the de facto standard for saving files has been Microsoft (Research)'s proprietary formats on popular programs like Word, Excel, and PowerPoint. But tech geeks have long been waiting for a more open alternative to Microsoft's system. The biggest selling point of ODF files is that they can move smoothly between programs without ever being trapped in one place. As a result, rivals of the software giant like Sun and IBM (Research) finally see a chance to grab market share for their own office products.

The man who has become a symbol for this movement is Peter Quinn, the mild-mannered former CIO of Massachusetts. Last fall Quinn made it state policy that by January 2007 all state employees would begin saving their work in open-standard formats such as HTML, PDF, and ODF--files that would work on anyone's software, not just Microsoft's.

Quinn touched off a political firestorm. State lawmakers challenged the need for a switchover. And Quinn came under personal attack when the Boston Globe ran a story alleging he'd misused state funds for travel. (He was exonerated but quit his job soon after. "I was becoming a lightning rod," he says.) Quinn's replacement also supports open standards.

Microsoft, of course, is trying to counter the ODF movement. It will release a version of Office at the end of the year with a format called Open XML, which is working its way through the standards-approval process. But other local and state governments in the U.S., like Minnesota's, and European countries, such as Denmark, are now considering ODF.

"I think a number of people recognized at about the same time that Massachusetts could be the canary in the mine," says John Palfrey, executive director of Harvard's Berkman Center for Internet & Society. "It could play out in every one of the 50 states and in hundreds of countries around the world. If Massachusetts goes this way, will others follow?"