Won't that mean rejiggering all of today's Web pages? Not necessarily. Many Web pages are generated on the fly from databases, so adding metadata labels is simply a matter of changing the wrappers put around the data. And large software vendors, which have pooh-poohed the idea of the semantic Web for several years, have recently begun to change their view. "They have started to understand it," Berners-Lee says.
It is an enormously ambitious scheme: an attempt not just to make information available, but to organize it too. Back in 1991, however, the idea that the Web would become what it is today seemed just as implausible. So perhaps lightning will strike twice after all.