ASP.NET “Atlas” is a package of new Web development technologies that integrates an extensive set of client script libraries with the rich, server-based development platform of ASP.NET 2.0. “Atlas” enables you to develop Web applications that can update data on a Web page by making direct calls to a Web server — without needing to round trip the page. With “Atlas”, you can take advantage of the best of ASP.NET and server-side code while doing much of the work in the browser, enabling a richer user experience.
ASP.NET “Atlas” includes:
- Client script libraries that provide a complete solution for creating client-based Web applications. The client script libraries support object-oriented development, cross-browser compatibility, asynchronous calls to Web services, and behaviors and components for creating a full-featured UI.
- Web server controls that provide a declarative way to emit markup and client script for "Atlas" features.
- Web services, such as ASP.NET profiles, that can add useful server-side features to an "Atlas" application.
http://atlas.asp.net/quickstart/default.aspx