The World Wide Web Consortium has taken up Microsoft's cause in a patent infringement lawsuit by urging the U.S. Patent and Trademark Office to invalidate the related patent "in order to prevent substantial economic and technical damage to the operation of (the) World Wide Web."

In a long letter sent Tuesday by W3C Director Tim Berners-Lee to James Rogan, U.S. Under Secretary of Commerce for Intellectual Property, Berners-Lee claims that "prior art" - a legal term referring to technology in existence at the time a patent is applied for - proves U.S. Patent number 5,838,906 (the '906 patent) is invalid and that the USPTO should therefore re-examine the case for issuing the patent in the first place.

Last August, a jury in Chicago ordered Microsoft to pay $520.6 million in damages to Eolas Technologies and the University of California at San Francisco, the holders of the '906 patent, which covers the technology allowing interactive content to be embedded in a Web site.

Though the Redmond, Wash., software company is appealing the ruling, it is also making changes to Internet Explorer (IE) that may affect a "large number of existing Web pages," the W3C said in a statement Wednesday that accompanied a copy of Berners-Lee's letter.

"Removing the improperly disruptive effect of this invalid patent is important not only for the future of the Web, but also for the past," Berners-Lee said in the letter. "The '906 patent is a substantial setback for global interoperability and the success of the open Web," he added later in the letter.

Berners-Lee, is generally credited as leading an effort, with Robert Cailliau, to write the underlying protocols - including HTTP and HTML - for what later came to be known as the World Wide Web, at the CERN nuclear research center in Switzerland in the late 1980s. He also founded the W3C in 1994, of which Microsoft and a number of its competitors, such as Oracle, Sun and RealNetworks, are members.

The technology covered in the '906 patent was developed by Eolas president Michael Doyle at the University of California at San Francisco. The patent describes in part "a system allowing a user of a browser program ... to access and execute an embedded program object," or small computer programs, often referred to as "applets" or "plug-ins."

The IDG News Service is a Network World affiliate.