Web 3.0
The explosive growth of blogs, wikis, social networking sites, and other online communities has transformed the Web in recent years. The Web
2.0 revolution included the facebook, flickr etc affecting the masses. The rolling out of technologies like search, social networking, and multimedia file sharing was the aim of 2007 Web 2.0 Summit.

Toward Web 3.0
A new generation of Web applications, which technology journalist John Markoff called “Web 3.0” is being brought to the public. There has been undergoing years
of behind-the-scenes development. a slowly expanding
wave of activity is seen on the web 3.0. The Semantic Web started taking shape in the 2000. Development of the Resource
Description Framework was under
way at the W3C. XML and Web
services were favoured. The task of completing the standardization
of RDF Schema was done by nvolving many companies and the DARPA. The first version of OWL, became W3C
Recommendations. The Tool vendors and manufacturers
are reluctant to implement products
until they see a market forming. similarly, there was delay for the web 3.0 applications to take flight. But it had some differences from the standard chicken and egg problem, here data can be generated from a standard
database, mined from existing
Web sources, or produced as markup
of document content. a machine-readable
domain description, defined in
RDFS or OWL was already available.
Web 3.0 applications require
extensions to browsers, or other Web
tools. Many three-tiered Semantic Web
applications could be rolled out by the SPARQL. Semantic-Web-based applications
all hinge on one another.

for further details, see these pdf:
http://comp.leeds.ac.uk/webscience/talks..._web_3.pdf
http://ris.uvt.ro/wp-content/uploads/201...vanova.pdf