Software Freedom Law Center Publishes Analysis of Microsoft’s Open Specification Promise

Nonprofit Group Says Microsoft Promise Provides No Assurance for Developers

March 12, 2008

The Software Freedom Law Center (SFLC), provider of pro-bono legal services to protect and advance free and open source software, today published a paper that considers the legal implications of Microsoft’s Open Specification Promise (OSP) and explains why it should not be relied upon by developers concerned about patent risk.

SFLC published the paper in response to questions from its clients and the community about the OSP and its compatibility with the GNU General Public License (GPL). The paper says that the promise should not be relied upon because of Microsoft’s ability to revoke the promise for future versions of specifications, the promise’s limited scope, and its incompatibility with free software licenses, including the GPL.

Microsoft issued the OSP to address the issue of patent liability for implementors of Microsoft’s Open Office XML (OOXML) file format. The International Organization for Standardization (ISO) is currently considering whether to make OOXML an ISO standard, and it will decide by the end of March.

“Based on our review of the OSP, we do not recommend that free software developers rely on it for assurance,” said Karen Sandler, SFLC Counsel. “Because free software developers cannot implement OOXML freely, we urge that it not be approved as an ISO standard.”

The paper is available on SFLC’s Web site at

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