The 906 patent, owned by the University of California and licensed exclusively to one-man software company Eolas, describes how a Web browser can use external applications. The patent also earned that school and company a $521m (£312m) judgment after a federal jury found that Microsoft's Internet Explorer browser infringed on it.
After Microsoft made public planned changes to IE that held the potential to break millions of Web sites, the World Wide Web Consortium (W3C) last month urged the USPTO to re-examine the so-called 906 patent in light of W3C technologies that it said predated Eolas' patent.
Specifically, the consortium pointed out early HTML drafts by W3C director Tim Berners-Lee and W3C staff member Dave Raggett that it said qualified as prior art in the case.
The W3C's public call came as part of a larger campaign to identify prior art relevant to the Eolas case. Prior art is a similar invention that predates a patent, therefore invalidating it.
The USPTO responded quickly to the W3C's request, and on 30 October, the office initiated an order for re-examination. On Monday, that order was docketed to the patent examiner.
"A substantial outcry from a widespread segment of the affected industry has essentially raised a question of patentability with respect to the 906 patent claims," Stephen Kunin, the USPTO's deputy commissioner for patent examination policy, wrote in his order for re-examination. "This creates an extraordinary situation for which a director-ordered examination is an appropriate remedy."
Kunin specifically cited the technologies that the W3C had raised in its request for re-examination.
"A substantial new question of patentability exists with respect to claims 1-3 and 6-8 of the 906 patent in view of prior art acknowledged by the patentee in the 906 patent and the newly cited teachings of Berners-Lee, Raggett I and Raggett II," Kunin wrote.
The USPTO, University of California, the W3C, Microsoft and Eolas could not immediately be reached for comment.
One person involved in the case hailed the USPTO's decision, praising the office's responsiveness to concerns raised by industry and other Web advocates.
"The thing that's exciting to me is that the (US)PTO sort of made the ruling on the basis of how much interest there is in this issue on the Internet," said Dale Dougherty, a vice president of online publishing and research at publisher O'Reilly & Associates, who posted news of the USPTO's decision on the O'Reilly Web site. "And it seems that they felt they had to respond to it."
Dougherty testified in the trial on Microsoft's behalf to the effect that a Web browser called Viola constituted prior art to the 906 patent.
