I've been meaning to comment on this interesting article on the open-source technologies that enable and facilitate Web 2.0. While we often assume that Web 2.0 wouldn't be possible without open source, open source, for example, also helps make Google's economics work.
But in their article, Ted Goddard and Steve Maryka suggest that open source has a long way to go before it can drive the deep, synchronous social interaction that Web 2.0 demands:
An examination of the interaction models for existing social networking platforms like wikis and blogs reveals that they lack the instantaneous nature of true human interaction. This is an artifact of the synchronous Web model that must be overcome when we consider next-generation platforms envisioned in the Web 2.0 spectrum....In fact, if you sift through those eight million Google hits, you'll find only a handful of open source technologies that address the problems associated with pushing content asynchronously to the user through standard browser mechanisms.
The authors ultimately conclude that "yes, Web 2.0 is possible today with existing open source technologies," but it's clear that we have a way to go in improving and deploying open source to make it robust enough to power the next generation of Web services.
It seems equally clear, however, that if open source doesn't step up to the task, no other technologies will. Open source is the cutting edge of Web technology. Innovation on the Web happens first in open source. Looks like we have some additional work to do, but that's an opportunity, not a critique.