In the last several days Microsoft has shown that despite claims of acquiring a newly found respect for open principles and technology, developers should be cautious in believing promises made by this “new” Microsoft.

Microsoft filed suit against TomTom today, alleging that the in-car navigation company's devices violate eight of its patents -- including three that relate to TomTom's implementation of the Linux kernel.

When Microsoft first sued TomTom for patent violations in TomTom's Linux-powered navigation devices, I wasn't sure how much of a fight TomTom would put up. Legally TomTom was between a rock and a hard place. You can't use restricted-use patents in GPLed software.

Microsoft Corp. was sued by Dutch navigation-device maker TomTom NV, which claims the world’s largest software maker infringes four of its patents used for automobile navigation.
The suit comes less than a month after Microsoft filed a complaint with the U.S. International Trade Commission in Washington seeking to block some of TomTom’s U.S. imports.

TomTom and Microsoft have settled the patent litigation. Here's TechFlash's coverage. According to the Microsoft press release, TomTom will remove functionality regarding the FAT patents within two years, which is no big deal, frankly, and in the meantime, they are covered "in a manner that is fully compliant with TomTom's obligations under the General Public License Version 2 (GPLv2)"

This is exactly what we were afraid of. Last month, when Microsoft sued Dutch GPS-maker TomTom on the principle that parts of Linux -- which form the guts of TomTom's device -- violate Microsoft's patents, we hoped for a quick settlement.

Microsoft is suing TomTom in part because the guys from Redmond claim that TomTom's use of Linux in its navigation devices has violated three of its file-system related patents. One reason why Microsoft feels it can do this is that it already has patent cross-licensing agreements covering these patents with other Linux-using companies.

Here's the complaint filed by Microsoft against TomTom, NV and TomTom, Inc., alleging patent infringement, as PDF and as text. We'll be setting up a Timeline page for it after TomTom files its answer.

Linux Foundation Executive Director Jim Zemlin said in his blog yesterday (26th February) that the Microsoft patent infringement suite against TomTom, at least at present, does not appear to be a covert attack on Linux.