The second option is the ASP.Net AJAX "Value-Add" download, which contains additional higher-level features that were in previous CTPs (Community Technology Previews) of Atlas, but which wont be in the fully supported 1.0 Core version, he said.
The third option is the ASP.Net AJAX Control Toolkit, which contains 28 free, AJAX-enabled controls that are built on top of the ASP.Net AJAX 1.0 Core download. This effort is a collaborative shared-source project built by a combination of Microsoft and non-Microsoft developers. It is available via download on Microsofts CodePlex community source site.
The new Atlas beta also features enhanced support for the Safari browser.
"Previous ASP.Net AJAX CTPs didnt have great support for Safari," Guthrie said in his blog. "With this Beta, we have added Safari as a fully tested and supported browser. We are currently working on adding Opera support as well."
In addition, the new beta features enhanced debugging support.
In addition, Microsoft has added better compatibility with other AJAX libraries and has issued a source modification license.
Moreover, Guthrie said Microsofts plan is "to release a beta refresh in a few weeks that incorporates customer feedback, then ship an RC release after that, and then ship it as a fully supported 1.0 release once people feel it is ready." However, he said, the APIs "are pretty close to being final."
Jeff Prosise, co-founder of Wintellect, a Microsoft partner based in Knoxville, Tenn., said what really sets ASP.Net AJAX apart from other AJAX implementations is the client-side framework, which now goes by the name "Microsoft AJAX Library."