Navigation device-maker TomTom has settled its patent dispute with Microsoft, putting an end to the current round of litigation between the two companies. The terms of the settlement, which were announced by Microsoft on Monday, are said to be fully compliant with GNU's General Public License (GPL).

The conflict between Microsoft and TomTom, which publicly emerged in February, raised serious concerns within the open source software community. Microsoft alleged that TomTom's navigation products, which use the open source Linux kernel, infringe on a handful of Microsoft's patents. Two of the patents cited by Microsoft cover legacy compatibility features in Microsoft's FAT filesystem, support for which is implemented in Linux. Some feared that the lawsuit was the beginning of a patent litigation campaign by Microsoft against embedded Linux adopters.

TomTom responded to Microsoft's lawsuit earlier this month by firing back with a coutersuit, alleging that Microsoft had infringed some of its navigation patents. As the conflict escalated, TomTom joined the Open Invention Network (OIN), an organization that has accumulated a defensive patent portfolio for protecting Linux from patent infringement lawsuits. This move led to speculation that the dispute could lead to a major patent showdown between the OIN and Microsoft.

That possibility has been averted—for now—by the settlement agreement. In an announcement Monday, Microsoft and TomTom contend that the terms of the settlement fully conform with TomTom's obligations under the GPL, the license under which Linux is distributed. TomTom has paid to license Microsoft's patents, including those covering FAT.

TomTom will, however, remove the functionality that is covered under the FAT patents. This will guarantee that the code in TomTom's Linux kernel can continue to be broadly redistributed downstream without patent encumbrances. This aspect of the agreement, along with specificity about which patents are infringed, are major factors that differentiate this agreement from Microsoft's controversial deal with Novell.

"This agreement puts an end to the litigation between our two companies. It is drafted in a way that ensures TomTom's full compliance with its obligations under the GPLv2, and thus reaffirms our commitment to the open source community," said TomTom IP director Peter Spours in a statement.

TomTom intends to make the requisite changes to the FAT code within the next two years. The company's agreement with Microsoft provides a guarantee that it will not sue TomTom users in the interim.

Although the settlement has ended the conflict between Microsoft and TomTom, questions still remain about the implications for FAT in the broader Linux ecosystem. Microsoft has previously stated that this lawsuit represents an isolated issue and that the company does not intend to broadly sue Linux users. Upstream kernel developers could potentially adopt TomTom's code changes in order to avoid future patent disputes with Microsoft over FAT.