Microsoft and non-profit licensing organization Creative Commons said Wednesday that they had struck a deal to allow Office users to add the group's licensing to their documents. Although the two companies have worked together in the past, this latest agreement is the most significant project to date.

The first document to be licensed through the Office tool is a speech by Brazilian Minister of Culture Gilberto Gil, which will be made at the Creative Commons iSummit in Rio de Janiero, the two companies said.

Such a deal could catapult Creative Commons from a fairly small user base to much wider acceptance as a method for protecting one's work. Microsoft estimates that there are some 400 million Office users worldwide.

The tool, which is available as an add-in for Office, can be downloaded through Microsoft Office Online or the Creative Commons Web site. CC licensing would be available for Word, Excel and PowerPoint documents.

"The goal of Creative Commons is to provide authors and artists with simple tools to mark their creative work with the freedom they intend it to carry," founder Lawrence Lessig said. "We're incredibly excited to work with Microsoft to make that ability easily available to the hundreds of millions of users of Microsoft Office."

Users of the add-in would be able to select from a variety of licenses available from Creative Commons. Additionally, the add-in could be used to allow work to become part of the public domain.

"The collaboration of Microsoft and Creative Commons to bring Creative Commons licenses to Microsoft Office applications underscores how for-profit companies and nonprofit organizations can work together to bring innovative ideas and tools to the public," said Alan Yates, general manager of the Information Worker Division at Microsoft.

Lessig added that Creative Commons is looking into ways to help protect other file types, including audio and video. However, it is unclear if Microsoft would open up its Windows Media Player to different licensing.