Web 2.0, the name we gave this phenomenon in 2004 when we named our new conference, turns five on Oct. 5 (the anniversary of the first Web 2.0 Summit). In our ongoing quest to understand where technology is taking us, the milestone serves as an opportunity not so much to look back but to examine the landscape ahead. Whereas the advent of Web 2.0 marked a profound shift in the meaning of the Web, this next phase is less a new direction than an exploration of what becomes possible when the building blocks of Web 2.0 (such as participation, collective intelligence and so on) increase by orders of magnitude.
We call this step Web Squared.
— Tim O’Reilly, writing in Forbes.com.