8 March 2004 The US Patent and Trademark Office (USPTO) has nullified the patent at the centre of a $521 million lawsuit by Eolas Technologies against Microsoft.

Eolas claimed Microsoft had infringed its patent, filed in 1994, which describes how plug-ins and ‘applets’ such as Flash animation or media players can run on web browsers. It was ordered to pay Eolas more than half a billion dollars.

The latest ruling will not only spare Microsoft from having to pay out the $521 million damages claim, but also means that it will not have to alter Internet Explorer to remove the offending elements — which would have ‘broken’ many web pages that use plug-ins.

But Martin Lueck, Eolas’s lawyer, said his client would fight the USPTO’s decision. He said such upsets were “somewhat routine and typical” and was confident that Eolas’ claim would be upheld. However, the USPTO has only invalidated 151 out of nearly 4 million patents awarded since 1988.

The decision to review the patent was triggered by a letter from Tim Berners-Lee, the director of the World Wide Web Consortium and author of the hypertext mark-up language (HTML), which underpins the Worldwide Web.

Berners-Lee said that instances of ‘prior art’ (previous examples of the technology’s use) should invalidate the patent.

Another review request was also made by an unnamed group, prior to Berners-Lee’s letter; message boards have speculated that Ray Ozzie, founder of Lotus and now a Microsoft employee, was behind this submission.

Eolas has 60 days to appeal against the USPTO’s decision.