Since the emergence of Google Maps, Ajaxprogramming techniques have become one of the hottest topics in the programming arena. To date, the frameworks available for creating these applications have been complex and have separated the development of the client-side Ajax (on the user's machine) from the server-side supporting technology (on the company's machines). This separation has made development slow and difficult.
ASP.NET AJAX is Microsoft's solution to this problem. ASP.NET AJAX (formerly code-named Atlas) is a set of extensions to the existing ASP.NET 2.0 technology that provides you with a fast-and-simple environment to create Ajax applications.