Some two decades after the creation of the World Wide Web, its inventor says the work is far from over.

Tim Berners-Lee encouraged 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," Berners-Lee said at a ceremony at the European Organization for Nuclear Research, known as CERN. "The Web is not all done. It's just the tip of the iceberg."

The ceremony Friday marked the Web's 20th anniversary, though it's an early celebration of sorts.

Berners-Lee first proposed the Web 20 years ago, in 1989, while developing ways to control computers remotely at CERN. He didn't begin writing software until October 1990, and his browser wasn't working until later that year.

In fact, Berners-Lee isn't even sure when exactly he wrote his first proposal for using the Internet, already two decades old at that point, 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 said. "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.

And he had to do all of that quietly: He never got the project formally approved, but his boss suggested he quietly tinker with it anyway.

Essentially, the Web combines two concepts that date to the 1960s: the Internet and hypertext, which is a way of presenting information nonsequentially. Though the two concepts were well known among engineers, Berners-Lee saw the value of marrying them.

The Web has since expanded rapidly.

"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 the completion of repairs 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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