In June 2004 the USPTO (U.S. Patent and Trademark Office) said it would re-examine the patent Microsoft Corp. holds on FAT, a format used for the interchange of media between computers and digital devices.
That followed the request to re-examine the FAT patent, made in April by the Pubpat (Public Patent Foundation), a nonprofit public service organization that describes its mission as "protecting the public from the harms caused by wrongly issued patents and unsound patent policy."
In September of last year, the patent office initially rejected Microsofts FAT patent application.
Now, this week, the USPTO rejected what are known as the Microsoft 517 and 352 patent applications, involving the long-file-name technology that is inherent to FAT.
Microsoft officials said the USPTO rejected the applications over an inventorship issue.
"The examiner has requested evidence that all six of the named inventors are properly named as inventors on the patent," company officials said in a written statement.
"Microsoft has an opportunity to submit evidence in response to the examiners request and remains optimistic that these issues will be resolved in its favor."
Microsoft officials said their reaction was upbeat because the USPTO did not reject the patent applications on the basis of prior art claims. In fact, according to David Kaefer, Microsofts director of business development, the USPTO ruled in Microsofts favor on all of the FAT prior art claims, including the prior art submitted by Pubpat.
"Although Im pleased that the PTO has maintained its rejection of the FAT patents, I am disappointed that they have withdrawn the prior art based portions of the rejections," said Dan Ravicher, executive director of PubPat. "If the FAT patents were to get re-issued by the Patent Office, we will consider our options at that time, taking into account the fact that due to the ex partes nature of the re-examination process, we have been precluded from submitting further evidence of the invalidity of the patents."
Microsofts Kaefer, understandably, had a different take.
"The question over whether these (517 and 352) are quality patents has been settled," Kaefer said. "The public was called in [to submit their opinions] and these patents stood up."
Kaefer said he expected the settlement of the issue of prior art to grease the wheels for more potential FAT licensees to sign agreements with Microsoft for the technology. Microsoft began licensing FAT to interested parties in December 2003.
"We now have more clarity on that [prior art] issue for them," Kaefer said.
Kaefer said he was not sure how many companies have licensed the FAT file system so far via Microsofts program.
FAT is used by some open-source software to facilitate the exchange of data between Linux and Unix computers with Windows computers.
Some in the open-source community, like Eben Moglen, who is a Columbia University law professor, the general counsel for the Free Software Foundation and a board member of Pubpat, have expressed concern that Microsoft could in the future decide to allege that Linux infringes on those patents and seek a royalty.
That could threaten the very core of Linux, which is licensed under the GNU GPL (General Public License) and may not be distributed if it contains patented technology that requires royalty payments.
"If Microsoft successfully commercializes its six FAT patents—we attacked the oldest and narrowest of them—as it is trying to do with hardware manufacturers like those of flash cards and digital cameras that format such file systems manufacturers, then it could be possible for Microsoft to argue that anybody using a free software system that reads and writes to the MS DOS FAT file system also has to pay a royalty. Everyone has grown accustomed to using those file systems on low-density removable media," Moglen told eWEEK previously.
But the issues surrounding the FAT patent still appear far from resolved, and there have already been many twists along the way so far.
Microsoft claims it developed FAT in 1976. FAT has become a ubiquitous format, used for data storage and data interchange between computers and digital devices such as cameras and USB memory sticks.
(This story was updated on October 5 to include comments from Pubpats Ravicher.)