Which came first? Web 2.0 or Web 3.0 Technologies?
Some (notably Tim O'Reilly) define Web 2.0 as a participatory movement. The evolution of WebPages into a two-way "interactive" medium can be seen as a consolidation of email, chat and newsgroups that were popular since 1980s. These e-communication paradigms became more public in nature - transforming into blogs and social networks. Written in HTML pages - rather than pure text files.
In effect, Web 2.0 was the remoulding of old communication paradigms into a Hypertext driven world. Newsgroups were wild social networks. Newsgroups were blogs that had no response control. The point is that global human participatory interaction over the net was identifiable since the 1980s.
Since 1996, XML - a derivative of SGML which rose out of IBM in the 1960's - has been touted as the next lingua-franca of the net. RDF, OWL and other XML languages and standards were proposed and formulated between 1997-1999. Semantic web started effectively circa 1998 as an identifiable paradigm.
In the history of the web, Web 2.0 may probably be remembered as a distraction. It is not surprising that Tim Berners-Lee discouraged the notion of Web 2.0 as being significant.
Web 2.0 may be identified as the time we took our eyes off the web - and started looking at ourselves as the center of a self-less web. It may be marked as the time when the selfish "we" became the center of a form-less web.
Now we are back to the roots again. We are back to making machines understand us.
Web 3.0 is truly an enigmatic mixture of machines and information - a space where men go like spiders looking for entertainment, news, food, love, work and life. Far from being participants, humans are becoming part of the web.