Internet luminary Tim Berners-Lee has made a personal appeal to the director of the US patent office to revoke a patent that threatens massive damage to the Web.

The Eolas patent – which is held by Eolas Technologies and the University of California – was found to cover the technology used in embedding interactive elements within Web sites. It is often used with video players, virtual tours, games and stock information.

Apple most recently released a slew of developer notes for Mac users, warning them of how to proceed to make required changes to their sites in order not to offend the Eolas patent. The patent could affect a wide range of technology companies with products that interact with Web browsers, or services that rely on customer interaction through browsers.

Berners-Lee – who is the director of the Worldwide Web Consortium – has written to the patent office asking for a "reexamination" of the granting of the patent: "In order to prevent substantial economic and technical damage to the operation of World Wide Web."

Legacy pages

The letter also refers to existing "prior art" that has been identified, which invalidates the patent. Berners-Lee argues that: "The impact of the patent reaches far beyond a single vendor and even beyond those who could be alleged to infringe the patent. The existence of the patent and associated licensing demands compels many developers of Web browsers, Web pages, and many other important components of the Web to deviate from the fundamental technical standards that enable the Web to function as a coherent system."

He also argues that enforcing the patent will mean that developers will have to rewrite their sites – with concurrent costs. "Given the interdependence of Web technology, those who wrote Web pages or developed software in reliance on Web standards will now have to retrofit their systems in order to accommodate deviations from standards forced by the patent."

The letter also argues that object-embedding technology covered by the patent has "been part of the HTML standard since the early days of the Web."

Its an important element to online content. "Nearly every Web user today relies on plug-in applications that add services such as streaming audio and video, advanced graphics and a variety of special purpose tools," it says.

Fearing serious implications against the online world, a World Wide Web Consortium briefing argues: "Changes forced by the patent will have a permanent impact on millions of historically important Web pages. In many cases, these pages contain non-commercial content or older material that is not generating revenue."

Berners-Lee adds: "The Web functions only on the strength of its common standards. The cost of widely divergent implementation of standards is borne by all who rely on the Web. The enormous expense and the more general threat the patent poses to the Web community is completely unwarranted because the patent is, we firmly believe, invalid in view of the prior art described."