Well, it’s finally happened. Microsoft, which has only sued two other companies for patent infringement in its whole life, is exercising its patent rights over Linux and suing TomTom, the Dutch-based portable GPS device house, for ignoring its pleas to license its patents like other GPS system makers have.  It accuses TomTom of both direct infringement and induced infringement.

Actually Microsoft is suing TomTom on eight counts of patent infringement, five of which have nothing at all to do with Linux. But the other three do and that’s what’s bound to make a big noise.

Click here to view a PDF of the Verified Complaint

In fact Microsoft is trying not to make too big a deal of the matter and is issuing statements saying, “Open source software is not the focal point of this action. The case against TomTom, a global commercial manufacturer and seller of proprietary embedded hardware devices, involves infringement of Microsoft patents by TomTom devices that employ both proprietary and open source software code.”

That’s hardly the point.

For years now Microsoft has claimed that Linux infringes on its IP but it has never substantiated those claims in any way. This is the first time it has put some meat on the bone or even identified some of its claimed IP.

Besides filing suit Wednesday in federal court in its hometown of Seattle, Microsoft also took its case to the International Trade Commission (ITC) in D.C. asking that TomTom’s Chinese-made widgets be barred from U.S. shores.

The stubby lawsuit is a dry, colorless affair that never mentions Linux; the 25-page ITC complaint, even in its redacted form, is more substantive. And the three “Linux” patents are the core of its complaint.

According to Microsoft’s story it has been chasing TomTom for over a year trying to get it to license its patents. That’s why its suit demands treble damages for willful and deliberate trespass.

The three provocative Linux-involving patents that Microsoft says TomTom is treading on are U.S. patents 5,579,517 and 5,758,352 both entitled “Common Name Space for Long and Short File Names” and 6,256,642 entitled “Method and System for File System Management Using a Flash-Erasable, Programmable, Read-only Memory.”

Microsoft explains to the ITC that TomTom’s GPS widgets run a version of Linux and that Linux “and/or the software applications supported by the operating system also provide the devices with additional functionality such as file system support for long and short file names, memory management for flash memory commonly used on such devices, and a platform for integrating and controlling various electronic components used with the portable navigation computing devices, such as other components in a vehicle.”

Microsoft says patents ‘517 and ‘352 “describe an innovative system that both supports long file names and maintains compatibility with file name system and applications that are aware of only short file names” so “a short file name system can read the directory entry containing the short file name but will ignore the directory entry (or entries) containing the long file name. A long file name system can access and manipulate these long file names and so in such a way as to ensure compatibility with the short file name system.”

Microsoft also explains that “file systems are the part of an operating system that manages files on a storage device. A common way of managing files is to use a hierarchical structure, often referred to as ‘folders’ or ‘directories.’ These directories contain files and often other directories or subdirectories. These traditional file systems were designed for ‘multiple-write’ devices rather than ‘single-write’ devices such as flash memory. The ‘642 patent describes a file system that supports the byte-addressable and block-erasable nature of flash memory, while providing support for a file system offering the functionality of traditional file systems.’

Click Here to See PDF of Microsoft's Complaint for Patent Infringement

Microsoft says it uses ‘517 and ‘352 in Vista and XP (remember FAT16) and ‘642 is used in Windows CE.

Microsoft also tells the ITC – in case the open source community thinks it’ll just get the patents declared invalid – that both ‘517 and ‘352 withstood re-examination by the Patent and Trademark Office. Both were issued in 1996 and reconfirmed 10 years later. Patent ‘642 dates to July of 2001.

There appear to be both Canadian and German counterparts to ‘517 and ‘352 that Microsoft has challenged.