Another name for the new wave of internet and sociak software in the 2000s
Basically SocialSoftware and all the other higher-order, parasitic services.
Going mainstream : http://www.gigaom.com/2005/02/06/web-20-time-to-cash-carry/
TimOReilly defends : and http://radar.oreilly.com/archives/2005/08/not_20.html and explains further : http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html
yes, Google's introduction of page rank was absolutely a milestone in this evolution of the web, but what was once an isolated stroke of genius is now being understood as one of the keys to the new paradigm. There's a set of "Web 2.0 design patterns" -- architecting systems so that they get smarter the more people use them, monetizing the long tail via a combination of customer-self service and algorithmic management, lightweight business models made possible by cooperating internet services and data syndication, data as the "intel inside", and so on.
Update : September 2005
Now there's a map : http://www.flickr.com/photos/36521959321@N01/44349798
And everyone's asking what it really is.
"What are the 3 big themes that undergird the upgrade?"
open data. You open whatever data you have, and positively encourage others to take it and "join" / "remix" it with their own. Plenty of people always understood this, but were probably swamped in web 1.0 by an influx from traditional media who tended to see data as something they created and sold access to.
specialization. Open data allows more niche re-users. One company doesn't have to do it all. It's a distributed bazaar where you can get famous (and possibly rich) doing one thing really well, as long as you're plugged into the ecosystem in the right way. Being well plugged-in is probably more important than having a stunningly good and original idea, or great execution. The irony here is that people who get famous doing one thing well, then get rich by being bought by a bigger conglomerate.
automation. For now, RSS and search engines. I guess we'll see further developments in crawlers, scutters, search and inference engines etc. With or without RDF. The important point is that integration doesn't just happen in the brain of the user any more.
AJAX I'm ambivalent about. It makes cute interfaces, which seem like a big deal to some people. But if we didn't have AJAX we'd probably be doing more with custom client software as was already happening with things like iPodder, Flickr's Uploadr, RSS aggregators, Napster etc.
Of course, the smart people (like Winer) could see all this years ago. But OReilly think of memes as platforms they can own. I guess this does help to get a bundle of ideas more widely distributed, and to a certain extent provides a shared vocabulary we can use to communicate more effectively.
Lots of people will misunderstand it all, though.
Update : further discussion leads me to think of a spectrum : /DeveloperSpectrum
OReilly's recent explanation put much emphasis on DataInside and owning (and embracing) data-platforms, with a similar emphasis on namespaces and owning identifiers. I didn't notice that in the web 2.0 discussion but it absolutely fits in with something I have long considered an essential thing to be understood : AddressableThings (and their relation with platforms)
RyanKing says its the web renaissance : http://theryanking.com/blog/archives/2005/10/05/the-dark-ages-of-the-web/
Some other definitions : FivePartWebTwoPointZero
DavidBerlind says it's the UnComputer
December 2005, backlash in full swing : http://www.crunchnotes.com/?p=88
My thoughts. Yep, it's a marketing term. Yep, it gets abused. Yep, lots of people throw it around without understanding it. I still think it's still a sometimes handy way of talking about many things I think are cool and important. When it helps communicate I'll still use it. When it gets in the way, I'll try to use some other term.
See also :