Original URL: http://www.theregister.co.uk/2009/07/07/vfat_linux_patent_patch/

Linux patch sidesteps Microsoft's TomTom patent

VFAT gets trimmed

By Gavin Clarke

Posted in Software, 7th July 2009 23:14 GMT

A Linux patch has been released to circumvent a Microsoft patent that landed Linux user TomTom in hot water.

The patch avoids the need to create both short - 8.3 - and long filenames, the crux of Microsoft's patent dispute with TomTom. Instead, you create one or the other.

Microsoft holds the patent on the Virtual File Allocation Table (VFAT) file system variant that lets you create the short and long filenames.

Samba author and contributor Andrew Tridgell, who posted about the Linux patch, warned that people should apply the patch even though Microsoft's VFAT patent might be invalid.

That means software developers and makers of common consumer goods ranging from mobile computing devices to digital cameras that run on Linux and use file systems.

Tridgell warned that Linux vendors risked having their businesses severely disrupted if they ended up fighting Microsoft over VFAT. A community peer-review process is underway looking for prior art to challenge VFAT, but it is far from complete so the patent still stands.

Tridgell said it was best not to infringe the patent, thereby avoiding a potential trial.

"That means you have to have an extremely clear explanation of how the patent does not apply to your code. The aim of the patches we have posted is to ensure that we would meet that standard," Tridgell wrote here.

During the TomTom case Microsoft pursued its patents through a US court and the International Trade Commission (ITC). A victory at the ITC would have seen Netherlands-based TomTom's popular in-car navigation devices banned from entering the US.

Naturally, this would have severely damaged TomTom's business.

It's the fifth time in seven years Microsoft has turned to the ITC on alleged patent violations, with four of those cases occurring within the last three years.

Microsoft has brought actions against Ultimate Game Club, Belkin, Alcatel-Lucent Enterprise and Primax Electronics. It secured the limited exclusion of products and components by Ultimate Game Club from the US, and saw Belkin and Primax sign up to its Hardware IP Licensing Program. Alcatel-Lucent was found not guilty of violations.

Microsoft settled with TomTom in March under an agreement that TomTom will pay Microsoft for use of its patents for five years and also tweak its Linux-based GPS systems to remove a pair of file-management patents. ®