The three US patents were among eight which Microsoft cited when suing the Dutch portable navigation device maker in February this year. The case was later settled after TomTom had counter-sued Microsoft.
The patents, all of which are part of TomTom's implementation of the Linux kernel, are:
1. and 2. Common name space for long and short filenames (two separate patents); and
3. Method and system for file system management using a flash-erasable, programmable, read-only memory.
OIN chief executive Keith Bergett said in a release that Linux Defenders'' patent vetting activity provided an opportunity for the Linux community to bring its collective knowledge to bear on the issue.
Submissions can be made by visiting the Post-Issue Peer to Patent site, clicking on the appropriate patent and selecting "Submit Prior Art".
In April 2004, the Public Patent Foundation asked the US Patent and Trademark Office to revoke one of the FAT file system patents which figured in the TomTom case.
This was after Microsoft announced in December 2003 that it would be charging a fee from those who used the filesystem; the company obtained this patent in November 1996. The FAT file system was introduced in DOS 2.0 in 1982.
In October 2004, the patent was rejected by the USPTO but later reinstated in 2006. At the time, Daniel Ravicher, the executive director of the Public Patent Foundation, said the loss was due to a flaw in the patent system - any organisation bringing a challenge to a patent was not given an opportunity to rebut the patent holder's claims after its initial challenge.
OIN is a group that enables innovation in open source by acquiring and licensing patents, and influencing policy. Post-Issue Peer to Patent is a project of the Centre for Patent Innovations at New York Law School.