Computer scientists, engineers and journalists converged on the CERN particle physics lab in the suburbs of Geneva, Switzerland, today to pay homage to a piece of paper—several pieces of paper, actually—that together form Tim Berners-Lee's March 1989 proposal that would come to be the blueprint for the World Wide Web.

Berners-Lee, the one-time CERN software consultant who went on to invent the Web and found the World Wide Web Consortium (W3C) at the Massachusetts Institute of Technology (M.I.T.), began his keynote today commemorating the 20th anniversary of his proposal with a copy of his now-famous document in hand. "I wrote it 20 years ago, 20 years ago nothing happened," he said, referring to the seven months the proposal languished on his supervisor's desk before in September that year he was given money to buy some computers and pursue his idea. (For more coverage of the Web's 20th anniversary, see  Scientific's in-depth report.)

The Web came to life on Christmas day 1990 and grew exponentially from that moment on. One of the reasons for the its phenomenal success was Berners-Lee's insistence that there be one Web for everyone to use, regardless of the type of computer, software program or documents they were using. For years, he says he was concerned that the original Web would split into many specialized webs, such as one for academia and another for businesses. But in the end his vision prevailed. "Universality," he said, "that was the rule, and it worked."

In a speech that touched on the past but also emphasized the Web's future (including its potential benefits as well as dangers), Berners-Lee pointed out that there are 100 billion Web pages today, roughly the same number of neurons in the human brain. The difference, he added, is that the number of pages grows as the Web ages, whereas the number of nerve cells shrinks as we get on in years.

"One of the dangers of celebrating anything is having people look back and [focus on] what we did," he said today. "But the rate of creative new design on the Web is getting faster and faster. The Web is not done; it's just the tip of the iceberg. I'm convinced that the things that are going to happen will rock the boat even more."

One of the W3C's priorities is promoting access to the Web via mobile devices, phones in particular. "There are more browsers on phones than on laptops, by a long shot," Berners-Lee said. Another major priority is maintaining the universality that he had in mind when he envisioned the Web. "Eighty percent of people can't access the Web," he said, because, among other reasons, they can't get a connection or the Web pages they access are written in a language they can't read.

As the Web grows, so do concerns about the confidentiality of private info on it. The main worry is that a hacker will access and use personal information such as credit card, banking account or Social Security numbers. One possible way to avoid this, says Berners-Lee, is to specify how the data may be used. "As the data is moved around," he said, "the appropriate use is tagged along with it." The tag, or set of instructions accompanying the data, would prevent it from being misused.

This suggestion is part of Berners-Lee's vision for a "Semantic Web" that would be easier to surf than the Web is today. In the Semantic Web, search engines would focus more on finding the information you're looking for, rather than simply locating Web pages that might contain that information. One way to do this, he said, would be to change the way new data is added to the Web so that it can be immediately linked to other data, making it easier to find. W3C is working on a way to do this through its Linked Open Data project, a key component of the Semantic Web.

An example of how the Semantic Web would work, which the W3C has posted to its Web site: you could populate your Web-based appointment calendar (such as those offered by Google or Yahoo) with appointments  as well as with other dated information to which you have access (such as bank statements and digital photos).

Image of CERN's Globe building, where Tim Berners-Lee and others celebrated on March 13, by Jim Shank via Flickr