(Caveat: this is indeed a retread, but the original content has been sufficiently revised that I’m electing to republish.)
While most of the Web 2.0 focus has been on the consumer (Zimbra being a notable exception), I visited a large corporation (call it Acme) that was working on their response to these new technologies and business models, and calling the overall effort “Acme 2.0”. Ouch. (On the choice of name, that is—I think the effort is a fine idea.) My fear is that like “.Com” before it, Web 2.0 is at risk of overheating as a buzz word. I think we are seeing this in some of the softer marketing slogans such as “Collaborative Web” or “Live Web”.
As a technologist, I admittedly tend to retreat toward more formal definitions anyway, but I think a technical definition could ultimately provide higher clarity and hence better protect the evangelistic efforts to date of Tim O’Reilly, John Battelle, et al. who coined the term to begin with.
After all, Web 1.0 started off on a similar wave of confusing, consumer-focused hype. Today, however, there is a consensus that the broad range of consumer and business applications of Web 1.0 all relied on a common technology stack founded upon HTML and HTTP/S. Web 1.0 had a huge impact on both consumers and on businesses, and the range of applications that were shoehorned into the basic model far exceeded expectations.
My hope is the same thing for Web 2.0. For my $.02, the Web 2.0 technology stack is Web 1.0 plus:
(2) Inter-application communications via XML, SOAP, REST, etc. – Of course, Ajax leverages XML for the client browser application to server application communications, but this is just a special case of XML for Service-Oriented Architecture in general. SOA has been around for decades, but back then we talked about Enterprise JavaBeans, Stored Procedures, CORBA, DCOM, DCE, MQSeries, and CICS/IMS transactions. The difference is that with the success of the Internet, XML, SOAP, et al., as well as Software as a Service, we have hopefully finally achieved critical mass.
(3) Collaboration-oriented Internet protocols – Email via SMTP (arguably also a “killer app” of Web 1.0) existed long before the World-wide Web, the now we are seeing explosive growth in new Internet protocols that provide the basis for enhanced collaboration: IM/XMPP, VoIP/SIP, RSS, and iCalendar are the best examples. Web 2.0 applications will increasingly been seen to be those that leverage these collaboration technologies as well as Ajax, SOA, and Web 1.0.
(4) Collaborative-authoring – Consider the success of blogging, Wiki (Wikipedia), tagging (Flickr, Del.icio.us), the mash-up, and now Ajax Linking and Embedding (ALE). (ALE in particular may prove to be a tipping point in terms of WYSIWYG authoring within the browser, which will allow users to far more easily create rich content.) I don’t think this category is complete yet, and it may ultimately just devolve into cool tricks for leveraging Web 1.0, Ajax, and XML, but for now I think this is where the Web 2.0 technical action is.