Web 2.0 generally refers to a second generation of services available on the World Wide Web that let people collaborate, and share information online. Unlike the first generation, Web 2.0 gives users an experience closer to desktop applications than the traditional static Web pages. The term web2.0 was popularized by O’Reilly Media and MediaLive International as the name for a series of web development conferences that started in October 2004. Web 2.0 applications often use a combination of techniques devised in the late 1990s, including public web service APIs (dating from 1998), Ajax (1998), and web syndication (1997). They often allow for mass publishing (web-based social software), the term may include blogs and wikis. To some extent Web 2.0 is a buzzword, incorporating whatever is newly popular on the Web (such as tags and podcasts), and its meaning is still in flux.

With its allusion to the version numbers that commonly designate software upgrades, Web 2.0 was a trendy way to indicate an improved form of the World Wide Web, and the term has been in occasional use for several years. For examples — “DoubleClick was Web 1.0; Google AdSense is Web 2.0. Ofoto is Web 1.0; Flickr is Web 2.0″ — rather than definitions.

What is now termed “Web 1.0″ often consisted of static HTML pages that were updated rarely, if at all. They depended solely on HTML, which a new Internet user could learn fairly easily. The success of the dot-com era depended on a more dynamic Web where content management systems served dynamic HTML web pages created on the fly from a content database that could more easily be changed.

Proponents of the Web 2.0 approach believe that Web usage is increasingly oriented toward interaction and rudimentary social networks, which can serve content that exploits network effects with or without creating a visual, interactive web page. In one view, Web 2.0 sites act more as points of presence, or user-dependent web portals, than as traditional websites. They have become so advanced new internet users cannot create these websites; they are only users of web services, done by specialist professional experts.

Overview of Web 2.0 techniques

A website could be said to be built using Web 2.0 technologies if it features a number of the following techniques:

Technical

  • Unobtrusive Rich Internet Application techniques (such as Ajax)
  • CSS
  • Semantically valid XHTML markup and/or the use of Microformats
  • Advanced User Interface languages such as XUL and SVG
  • Flash Remoting
  • Syndication of data in RSS/Atom
  • Aggregation of RSS/Atom data
  • Clean and meaningful URLs
  • Weblog publishing
  • REST or XML Webservice APIs

General

  • The site should not act as a “walled garden” – it should be easy to get data in and out of the system.
  • Users usually own their data on the site and can modify at their convenience
  • Mainly web-based – most successful Web 2.0 applications can be used almost entirely through a web browser
  • Data returns should be dynamic, not static, changing depending on variables associated with the user’s query (e.g. keywords, location).