Stirring Things Up

AJAX is a Web development technique for creating interactive Web applications using a combination of XHTML (or HTML), CSS, JavaScript, XML and other technologies. Why is this important? Simply put, AJAX applications look almost as if they reside on the end user&'s system, as opposed to being delivered across the Internet via a server.

FRANK J. OHLHORST

Can be reached at (516) 562-7485 or via e-mail at [email protected].

AJAX-based applications accomplish that feat by updating only displayed pages using DHMTL. It works by intercepting each user&'s HTTP request and replacing that request with a local JavaScript call to the AJAX engine. The key difference here is that traditional Web applications submit forms, completed by the user, to the Web server. The Web server then responds by sending a new Web page back. Because the server must send out a new page every time, applications run more slowly and awkwardly than their local counterparts would.

AJAX-based applications change the user&'s perception by creating an application experience that is almost indistinguishable from that offered by a traditional application. What&'s more, AJAX brings other functionality to the table, features such as drag and drop or multiple item selection and other capabilities normally found on desktop applications but not in traditional Web-based applications. For examples of AJAX in action, interested parties can take a look at Google Maps (maps.google.com) or Yahoo&'s new beta version of its Webmail service.

With all this in mind, it is easy to see how AJAX could change how applications will be built and delivered. It promises platform-independence, a quick development cycle and reduced server loads. And although AJAX is currently intended for Web-enabling applications, unplugged applications are around the corner. Companies such as Morfik and Tibco already offer tools to quickly build AJAX-based applications.

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