Tim O’Reilly has a new post titled Web 2.0 Compact Definition: Trying again. O’Reilly’s essay, which has received many comments, includes this ‘brief definition’ of the much discussed phrase:

Web 2.0 is the business revolution in the computer industry caused by the move to the internet as platform, and an attempt to understand the rules for success on that new platform. Chief among those rules is this: Build applications that harness network effects to get better the more people use them. (This is what I’ve elsewhere called “harnessing collective intelligence.”)