Microsoft Claims Linux Infringes 42 Patents

In a revelation certain to incite legal worries among the thousands of businesses that use open-source software, Microsoft has for the first time stated the quantity of its patents it believes Linux and other free software programs violate.

Microsoft general counsel Brad Smith said the Linux kernel itself violates 42 of the company's patents; Linux graphical user interfaces infringe 65; Open Office programs violate 45; various open source e-mail applications step on 15; while a number of other free or open-source software programs violate an additional 68 patents held by Microsoft.

The claims are made in a Fortune magazine article published Sunday. In the article, the Microsoft executive declined to say which specific Microsoft patents he believes are being violated, but maintains the total is 235.

Microsoft has long intimated that it believes Linux and other open-source software programs infringe on some of its patents, but the comments published in Fortune indicate that the company may now be ready to push its claims more aggressively -- possibly in court. "It's the first time that Microsoft has made a public statement in which a specific number of patents has been discussed," said Eben Moglen, a Columbia University law professor who is counsel to open-source advocates the Free Software Foundation.

Microsoft recently cut a deal with Linux distributor Novell, under which the two companies agreed not to sue each other, or each other's customers, for patent claims. Last week, Dell agreed to participate. However, customers of other Linux distributors -- from Red Hat to Ubuntu -- could be fair game for Microsoft's attorneys if it chooses to press its claims through litigation.Moglen said it's too early to say whether open-source software users should be worried about lawsuits. "What Microsoft has not done is identify specific patents, which is the only thing that, from the point of view of somebody who has been told he's infringing patents, cares about," said Moglen, in an interview with InformationWeek.

Many open-source software programs, including Linux, are copyrighted under the terms of the General Public License, which is authored and governed by the Free Software Foundation. A forthcoming, third major revision of the GPL would, in its current draft form, prevent Linux distributors like Novell from cutting any more mutual protection agreements with Microsoft or other commercial software companies in the future.

As a result, large corporate Linux users that aren't using the current Novell distribution would be left to either forego the OS altogether or take a chance that their use of the open-source operating system won't earn them a visit from Microsoft attorneys.

Microsoft officials were not immediately available for comment.