Typically the version numbers x.y with respect to a software application means there is a distinct point in time when this version was introduced. Usually the new release will have updated functionality. While the changing and improving functionality with time is true of the world wide web or just the web that we know; there is no distinct point in time when we can say the functionality changed to include improved ones from that time on. Thus there is no real web 2.0, nor a date & time when it became 2.0. Instead in the evolving ecosystem there are applications being developed that are philosophically different than what used to be available. What is happening is applications that use the web as a platform are coming about. The web infrastructure, the technology remains substantially the same. It is evolving slowly over time of course. In a way the changes are happening now out of the ashes of the dot com bust. So if the web prior to the bust was 1.0 version, we have web 2.0 coming about now.
Typically you use the web browser and then interact with a given site and get a lot of work accomplished. This interactivity with content is quite typical of the Web2.0 applications, as is interconnectivity of contents too. We shall look at some examples. An evolved form of this is software as an application (SaaS). There are several successful examples of this too.
The most well known example of web 2.0 probably are the social sites. MySpace started a trend followed by Facebook. Orkut is another such site. It was almost as if the people who spent time with their computers and did not interact socially; needed to socialize badly even if it was in the cyberspace. You went out to these sites and socialized, found friends, communicated with friends. Social bookmarking started another trend. You shared what you liked with others thereby making search for what’s good easier. Sites such as del.icio.us, ho.tli.st, sidereel etc are examples of this kind of sites. Dig, reddit, etc are some more examples. LinkedIn is a professional networking site. Second Life takes socializing to a whole new level. It is the social site for virtual characters.
Blogging is another web 2.0 phenomenon. Google’s Blogger provides an easy way of creating and owning a blog. WordPress adds provides many options that can let you customize sites so much that you can create full-fledged business sites. There’s almost a generation of websites with a diverse range of applications. Blogs have a started a whole new trend so that corporate bodies use it as a part of their marketing strategy, customer services strategies.
Sharing of photos, videos, music and files is on a whole different scale. Take Flickr or YouTube; they are each a trend in themselves. iTunes started a whole new trend in music retailing. Omnidrive, xdrive etc are places where you can store data off-site. Google Earth and other mapping sites, wikis, Wikipedia, knoll are a whole set of diverse applications. SaaS applications include productivity applications that you could use and just pay for the use or a nominal subscription. Salesforce.com is the most famous example. Quite often this is cited as one of the first Web 2.0 example. Google Docs is another example.