The royalty-free license under which Microsoft plans to make its upcoming new Office Open XML Formats widely available is incompatible with the GNU General Public License and will thus prevent many free and open-source software projects from using the formats, community officials say. In addition, a leading patent official is calling into question the validity and enforceability of the Microsoft Corp. license and suggesting that free and open-source software developers need not comply with its conditions.

Microsoft, of Redmond, Wash., first released its Office 2003 XML Reference Schemas in late 2003. Office officials said earlier this month that they planned to make the new XML file formats the default in Office 12, due next year, available to anyone under a royalty-free license. 

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