JavaScript/Ajax

Ajax (Asynchronous JavaScript and XML), is a method of employing JavaScript, DHTML, and the XMLHttp behavior in the browser to provide truly dynamic content on a Web page without a page refresh. Popular examples of this technology include Google's Suggest, Amazon's Diamond Search tool, and many of Flickr.com's interactive features.

Ajax effectively does away with the traditional "Click-and-Wait" Web-application architecture of yesterday, making it possible to provide the responsiveness and interactivity users expect from desktop applications. Ajax's ability to pull data from the server after the page has loaded contrasts with what we now refer to as the "traditional architecture." In a traditional architecture, the user must wait for the entire Web page to reload to see new results from the server. In an application that requires a lot of interactivity with the business layer sitting on the server, the user must reload the entire page many times. This has implications for the efficiency of workflow, the load placed on the server hosting the application, and the productivity of users.

• Reduces the number of round trips by minimizing the number of page transitions in a web application.
• Reduces the size of uploaded and downloaded data because it allows the web programmer to control exactly what is transferred. For example, if a user performs a search the data can be returned in a compact data format (e.g. JSON ) rather than HTML.
• Web based applications are used to replace desktop applications that had superior user interfaces. The benefits of offering users a similar or even just a familiar user interface to what they use on the desktop means lower training costs, fewer errors, and greater initial productivity.
• Ajax increased responsiveness. A responsive application can improve productivity not just by reducing ‘wait’, but by promoting a more fluid, uninterrupted workflow. In a responsive application, users can move rapidly from one action to another as quickly as they can visualize the workflow. Less responsive applications can defeat the user’s workflow visualization by forcing them to continually wait for program information.