The Software Freedom Law Center (SFLC) has dismissed Microsoft's patent pledge to open source developers as "meaningless" and warned that it could provide a false sense of security. 

The SFLC provides legal services to the open source community and is funded in part by the Open Source Development Labs as well as public donations. The organisation posted an analysis of Microsoft's pledge on its website. 

"A careful examination of Microsoft's Patent Pledge for Non-compensated Developers reveals that it has little value," concluded Bradley Kuhn, chief technology officer at the SFLC.

Microsoft and Novell signed a partnership earlier this month to collaborate on Linux-Windows interoperability, and provide legal indemnification to users of Novell's SuSE Linux distribution.

The agreement also included a patent pledge from Microsoft to individual open source developers.

But Kuhn argued that this pledge has very little practical value to the overall open source community, as it applies only to individual developers, excluding users from the patent umbrella.

While developers received a guarantee that Microsoft will not enforce its patent portfolio against them, the company can still go after individual users of the open source applications that the developers created.

"The pledge applies precariously to developers who work in a vacuum: those who write original software in their spare time, receive no payment for it, and do not distribute it to anyone under the General Public Licence," wrote Kuhn.

Microsoft has also added a "poison pill clause" to the pledge, allowing the company to retract its patent pledge at any time.

"Even if the patent pledge were to have some use aside from these problems, our community simply could not rely on it," said Kuhn.