To understand why websites and applications might be considered Web 2.0, we first need to agree on a definition of the term. While there is no formal definition for it, we believe there are three essential components to Web 2.0:
- Delivering a richer desktop-like user experience (Ajax).
- Exposing functionality as easily consumable services (web services).
- Leveraging the user-base to create, enhance, and categorize information.
The notion of Rich Internet Applications is all about delivering desktop-like experiences in the browser. JavaScript and Ajax are commonly used on the client side to deliver this experience. The main advantage of these technologies is their presence in popular web browsers, and that they can be implemented incrementally without requiring rewrites of existing web applications. In this model, the client depends on the server for orchestrating and delivering its data. PHP has been popular with Ajax applications because it's exceptionally well suited for this task. Not only is PHP a rich integration platform that includes connectivity to all popular databases, languages, file formats, and services, but it also has user-friendly and robust support for both the XML and JSON formats, typically used in client/server communications.
