Today Scott Guthrie, General Manager within the Microsoft Developer Division announced official beta release of ASP.NET AJAX v1.0 .
You can The ASP.NET AJAX v1.0 “Core” download. This redist contains the features that will be fully supported by Microsoft Product Support, and which will have a standard 10 year Microsoft support license (24 hours a day, 7 days a week, 365 days a year). The download includes support for the core AJAX type-system, networking stack, component model, extender base classes, and the server-side functionality to integrate within ASP.NET (including the super-popular ScriptManager, UpdatePanel, and Timer controls).
2) The ASP.NET AJAX “Value-Add” CTP download. This redist contains the additional higher-level features that were in previous CTPs of “Atlas,” but which won’t be in the fully-supported 1.0 “core” redist. These features will continue to be community supported as we refine them further and incorporate more feedback. Over time we’ll continue to move features into the “core” download as we finalize features in this value-add package more.
3) CodePlex today.