just in case you missed it, the web now has version numbers. nearly three years ago, amid continued hand-wringing over the dot-com crash, a man named dale dougherty dreamed up something called web 2.0, and the idea soon took on a life of its own. in the beginning, it was little more than a rallying cry, a belief that the internet would rise again. but as dougherty's o'reilly media put together the first web 2.0 conference in late 2005, the term seemed to trumpet a particular kind of online revolution, a world wide web of the people.

web 2.0 came to describe almost any site, service, or technology that promoted sharing and collaboration right down to the net's grass roots. that includes blogs and wikis, tags and rss feeds, del.icio.us and flickr, myspace and youtube. because the concept blankets so many disparate ideas, some have questioned how meaningful—and how useful—it really is, but there's little doubt it owns a spot in our collective consciousness. whether or not it makes sense, we now break the history of the web into two distinct stages: today we have web 2.0, and before that there was web 1.0.

which raises the question: what will web 3.0 look like?

yes, it's too early to say for sure. in many ways, even web 2.0 is a work in progress. but it goes without saying that new net technologies are always under development—inside universities, think tanks, and big corporations, as much as silicon valley start-ups—and blogs are already abuzz with talk of the web's next generation.

to many, web 3.0 is something called the semantic web, a term coined by tim berners-lee, the man who invented the (first) world wide web. in essence, the semantic web is a place where machines can read web pages much as we humans read them, a place where search engines and software agents can better troll the net and find what we're looking for. "it's a set of standards that turns the web into one big database," says nova spivack, ceo of radar networks, one of the leading voices of this new-age internet.

but some are skeptical about whether the semantic web—or at least, berners-lee's view of it—will actually take hold. they point to other technologies capable of reinventing the online world as we know it, from 3d virtual worlds to web-connected bathroom mirrors. web 3.0 could mean many things, and for netheads, every single one is a breathtaking proposition. — tim, lucy, and the semantic web