IN 2003, towards the end of the dotcom depression, Dale Dougherty and Tim O'Reilly, the founders of O'Reilly Media, a book publisher and conference firm, were brainstorming, and Mr Dougherty dropped the term “Web 2.0”. It was an allusion to the nomenclature for software upgrades, and Mr Dougherty was applying it to what he hoped would be a second generation of the internet. “We think of ourselves as an enzyme,” says Mr O'Reilly. “When we see something coalescing, we give it a name.”

In marketing terms, it has been a great success. In 2004 Mr O'Reilly and a partner, John Battelle, started a new annual conference, called Web 2.0, which has become a big event for Silicon Valley's aristocracy. “Web 3.0” is already discussed at Web 2.0, the conference.

But what is Web 2.0? It began with a specific and useful definition. In contrast to the static web pages of the 1990s, the second wave of websites would use software (such as AJAX, or “asynchronous JavaScript and XML”) that makes web pages look like dynamic software applications that traditionally run only on personal computers. These applications, moreover, would work with one another in so-called “mash-ups”. Google Maps, for instance, is a web page that not only updates itself constantly but can also share data with other websites to yield independent web pages that display, say, crimes committed or houses for rent in an area.

At some point “Web 2.0” took on a life of its own, being applied to online social networks, collective intelligence, blogging and podcasting and “participation” in general. It started being used in sentences that also contained other buzzwords, such as the “long tail”, “folksonomies”, or the “semantic web”. It is in danger of meeting the fate of “core”, “synergy”, and “leverage”, but, for the time being, Mr O'Reilly is delighted.