Scott Guthrie has some good info on project
Atlas, a Microsoft project to develop
AJAX tech for asp.net:
What we’ve set out to do is to make it dramatically easier for anyone to build AJAX-style web applications that deliver rich, interactive, and personalized experiences. Developers should be able to build these applications without great expertise in client scripting; they should be able to integrate their browser UI seamlessly with the rest of their applications; and they should be able to develop and debug these applications with ease. For this work, we’ve been working on a new project on our team, codenamed “Atlas”. Our goal is to produce a developer preview release on top of ASP.NET 2.0 for the PDC this September, and then have a website where we can keep updating the core bits, publishing samples, and building an active community around it.