The US Patent and Trademarks Office has thrown out two Microsoft patents on its FAT file system. The case had been raised by open source defenders who feared that Microsoft was preparing a legal offensive against Linux based on enforcement of intellectual property rights. But the Patent Office rejected the patents because of an administrative technicality - not because of prior art submitted by the F/OSS team.
In November 2003 Microsoft began to license its venerable FAT file system, written by Bill Gates himself for the original 1981 IBM PC. The file system was already in wide use in non-PC devices such as compact flash media used in digital cameras, so Microsoft was inviting vendors to pay for something that they already used for free. This alarmed open source advocates, who cannot use royalty-bearing patents with GPL software; Linux makes use of the FAT file system in the kernel. A non-profit group requested that Microsoft's claims for the patents be investigated.
The USPTO rejected one of the patents, (USPTO 5,579, 517, referred to as '517) in September 2004 in a preliminary ruling. Now it's struck down the other, on the grounds that it the six assignees names were incorrect.
"Microsoft has an opportunity to submit evidence in response to the examiner's request and remains optimistic that these issues will be resolved in its favor," said the Patent Office.
Back in March, Microsoft's chief attorney Brad Smith slammed the USPTO for lowering the quality of the patents it issued. But Microsoft had nicer things to say about the Office yesterday, commending it for upholding the patents' IP content.
The Public Patent Foundation, a non-profit, had argued that the two Microsoft patents were invalid because of three prior art patents, filed by IBM and Xerox in 1988, 1989 and 1990.
The IP issue remains a potent threat for Microsoft because of the very real difficulties that open source and free software developers have with royalty bearing patents. However, the difficulty of launching litigation means it's only really potent as a threat - like Mutually Assured Destruction, as we discussed here.
Earlier this year Microsoft's legal team advertised for patent attorneys, for which "no patent experience was necessary". ®