This week, Microsoft issued a copyright infringement suit in US district court and with the US International Trade Commission against Dutch PND maker TomTom, claiming the company has violated eight of Microsoft's patents. The move comes after a year of trying to engage in licensing talks with TomTom, Horacio Gutierrez, corporate vice president and deputy general counsel of intellectual property and licensing at Microsoft, said in a statement.

The patents Microsoft claims TomTom has violated: "Vehicle Computer System with Open Platform Architecture," "Method and System for Generating Driving Directions," "Methods and Arrangements for Interacting with Controllable Objects within a Graphical User Interface Environment Using Various Input Mechanisms," "Portable Computing Device-integrated Appliance," "Vehicle Computer System with Wireless Internet Connectivity," "Common Name Space for Long and Short Filenames" - which was cited twice because it was re-examined and then issued another patent - and "Method and System for File System Management Using a Flash-Erasable, Programmable, Read-only Memory."

This is reportedly the third time Microsoft has sued TomTom over intellectual property rights, but many are wondering what a suit against a Linux implementer means in the company's overall stance on open source. The move will strengthen the credibility of the licensing team who are going to be looking for licensing fees from smaller companies making mobile devices and netbooks in the coming months. Microsoft has reportedly established over 500 patent licensing deals since 2004.

Given the expense of litigation, the latest legal action is likely to end at the settlement table, but by filing with the U.S. International Trade Commission, it is clear that Microsoft means business. Microsoft is seeking "to obtain an exclusionary order barring the importation of TomTom devices at our border," Raymond Van Dyke, a technology attorney with Merchant & Gould, told LinuxInsider.