The inventor of the World Wide Web celebrated its 20th anniversary Friday by encouraging fellow scientists at his former particle physics laboratory in Switzerland to look to the future.

"The rate of development and innovation on the Web is actually getting faster and faster all the time," said Tim Berners-Lee told a ceremony at the European Organization for Nuclear Research. "The Web is not all done. It's just the tip of the iceberg."

Berners-Lee said he wasn't sure when exactly he wrote his first proposal for using the Internet to allow physicists to browse from page to page, share images and click on links to access other sites.

"The exact date, I'll have to admit, is sort of a created one because I can't remember which day it was I actually wrote the darn thing," Berners-Lee told the celebration at the organization, known as CERN. "I probably was thinking of it all through February."

He said it took a while to get an adequate computer and make the idea work, but that by December of 1990 the Web was up and running _ even if only between two computers at CERN.

It expanded rapidly, however, taking advantage of the Internet which had already been running more than 15 years.

"It took off because, across the planet, random people got involved," Berners-Lee said.

He said Web usage grew 10 fold every year.

"You think it's a great change to society that you can look things up on the Web," said Berners-Lee. But changes that are yet to come "are going to rock the boat even more."

"People use the Web to invent things, all kinds of things which you never would have imagined."

The celebration took place as scientists at CERN, near Geneva, were waiting for repairs to be completed to the laboratory's particle accelerator _ the world's largest atom smasher that was sideline by an electrical fault soon after its startup in September.

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