I hear a lot of discussion around defining Web 2.0; I think simpler definition is better such as “user based collaboration and content generation”. There are a number of people who want a clear cut definition on exactly what Web 2.0 is and everything encompassed by Web 2.0. This is analogous to asking for a list of every animal that exist now or has ever exist before they are willing to talk about dogs or buffalo. Even today new species are being discovered. If I may barrow the famous words of the late Supreme Court Justice Potter Steward, “I may not be able to fine it, but I know it when I see it.” Web 2.0 is still growing and evolving this is why it is still so hard to define.

The biggest issue facing Web 2.0 is not technology. Most of the technology used in Web 2.0 has been around for quite some time. It is the application of this technology which is special. Here is the analogy I use for those who say that there is nothing new in Web 2.0. Using this approach one could argue that there is no such thing as a democratic state. That before the 1700s there were people, states, and governments and democracy is just made of these three elements. Well, we know that it is not the elements but their application which is different.

Craig Tobias
Solutions Architect
Cisco Systems.

Here are 10 more definitions that Richard MacManus has collected:

John Battelle (talking about upcoming conferences): "eTech is where the seeds of new and interesting technologies are first discovered, whilst Web 2.0 is where they take root in the soil of business."

Kingsley Idehen: "...a Point of Presence on the Web for exposing of invoking Web Services and/or Syndicating or Subscribing to XML based content."

Wirearchy: "According to the experts, Web 2.0 is on its way to the workplace soon - it's an infrastructure that's decentralized and more open than that which exists today."

Jon Udell (as quoted in a classic essay by Tim O'Reilly): "Don't think of the Web as a client-server system that simply delivers web pages to web servers. Think of it as a distributed services architecture, with the URL as a first generation 'API' for calling those services."

The World 2 Come (talking about the Web 2.0 Conference in October 04): "The conference will debut with the theme of 'The Web as Platform,' exploring how the Web has developed into a robust platform for innovation across many media and devices - from mobile to television, telephone to search."

Deep Green Crystals: "The next generation of web applications will leverage the shared infrastructure of the web 1.0 companies like EBay, Paypal, Google, Amazon, and Yahoo, not just the 'bare bones transit' infrastructure that was there when we started..."

Jeff Bezos: "web 2.0...is about making the Internet useful for computers."

computeruser.com: "Yesterday's challenge of producing elegant and database-driven Web sites is being replaced by the need to create Web 2.0 'points of presence'"

Adam Rifkin: "They don't see that the power of Weblications is that "simplicity and flexibility beat optimization and power in a world where connectivity is key", as Adam Bosworth put it."

Mitch Kapor: "The web browser and the infrastructure of the World Wide Web is on the cusp of bettering its aging cousin, the desktop-based graphical user interface for common PC applications."