In the core of the RadAjax framework is a patent-pending technology, which can make selected controls on the page perform AJAX callbacks instead of traditional postbacks. The AJAX-enabled controls are not merely rendered with callbacks, but preserve their interaction with the server and relations with the other controls on the page. In fact, ajaxified controls do not really know that they are working with callbacks instead of postbacks. See a live demo.

A key disadvantage of other AJAX frameworks is the fact that you need to turn you application inside out and make major modifications in order to make it work with AJAX. You typically have to place Callback Panels around areas that need to be updated, set triggers, and manually invoke AJAX requests. In contrast, thanks to the patent pending Click-and-Go™ technology of Telerik RadAjax you only have to drag-and-drop the AJAX Manager on the page, tick the respective checkboxes in the dialog, and hit F5. You application is now AJAX-enabled. (Read more / Watch a video)

The Telerik RadAjax framework offers a completely codeless approach for AJAX-enabling existing or new web applications. Postback requests of selected elements are automatically replaced with AJAX callbacks so that you don't have to attach custom JavaScript functions to page elements and invoke AJAX requests manually. Furthermore, the elements that need to be updated after the server response are updated automatically by the RadAjax client-side engine.

The Telerik RadAjax engine can AJAX-enable any of the standard controls shipped with Visual Studio 2003 and 2005 and well as all of the controls included in the Telerik suite for ASP.NET. Most 3rd party controls are also supported, however due to some specifics of certain implementations full compatibility is impossible. See a live demo.

Telerik RadAjax uses a proprietary AJAX engine that works both on the 1.x and 2.0 versions of the .NET framework.

RadAjax does not break the normal page life-cycle, which guarantees the proper functioning of your applications. Actually, the AJAX-enabled controls don't really know that they are working in AJAX mode rather than postback mode.

All form values are sent to the server for processing during the AJAX request and are persisted between AJAX requests. All form controls can be referenced in the code-behind as if a postback occurred. This feature guarantees that your AJAX-enabled applications will not be limited to mere rendering of controls with AJAX, but can cover even the most complex scenario. See a live demo.

RadAjax controls re-initialize JavaScript code after an AJAX request has been performed. This behavior is very important when working with third party that feature rich client-side functionality like the Telerik RadControls for ASP.NET. The proper functioning of such controls will not be affected when they are AJAX-enabled with Telerik RadAjax. See a live demo.

RadAjax controls fully support server- and client-side validation implemented with the standard ASP.NET validation controls. See live a demo

RadAjax automatically detects and handles the web crawlers (search engines) by rendering alternative content, suitable for indexing.

RadAjax now allows you to perform client-side calls to web services and retrieve information via AJAX requests using simple or advanced web service invocation. See a live demo.

Reinforcing the idea of codeless development Telerik RadAjax now natively supports Response.Redirect during AJAX requests, without the need for any code modifications.

Most AJAX-enabling products offer just limited AJAX capabilities, allowing you to merely load/update a control with a callback. Those solutions, however, do not send form values to the server for processing, or do not preserve the ASP.NET page lifecycle. As a result you can implement only a limited number of scenarios. The Telerik RadAjax framework on the other hand can cover any scenario that can be implemented with the traditional postback mechanism. Resultingly, you can build very sophisticated applications, similar to Outlook Web Access or the Telerik HelpDesk sample.

RadAjax updates the ViewState of the page after the AJAX request in order to keep it in a consistent state regardless of the type of the request that has been made (AJAX callback or postback). See a live demo.