Microsoft has released a beta version of its AJAX (Asynchronous JavaScript and XML) programming technology, formerly code-named Atlas and now called Microsoft ASP.Net AJAX v1.0.

AJAX has become a popular technique for building rich Internet applications. Microsoft's offering in this arena is the former Atlas technology.

The beta offering is available in three download options, said Scott Guthrie, a general manager in the Microsoft Developer Division, in his blog. These include the following:

-- A "Core" download, with features to be fully supported by Microsoft including the core AJAX-type system, networking stacking, and component model.

-- A "Value-Add" CTP download with higher level features that were in previous community technology preview but not fully supported in the 1.0 core. Over time, features will be moved into the core download.

-- A Control Toolkit, with 28 free controls built on top of the core download.

The beta features several changes in areas such as performance and download size optimizations, the addition of Safari browser support, better debugging, UpdatePanel improvements, and enhancements to the client script library stack. Better compatibility with other AJAX libraries also is featured. A license will be provided to allow custom modifications of the libraries.

"Previous ASP.Net AJAX CTPs (community technology previews) relied on the browser downloading a single large, JavaScript file to the browser that contained all of the features, Guthrie said. "With this beta release we have spent a lot of time on factoring out features into multiple files, so you don't have to download them unless you use them, and in optimizing the bandwidth size of the overall library."

"We are really looking forward to having lots of people use the Beta and to getting more feedback," Guthrie said. A beta refresh is due in a few weeks that will incorporate customer feedback, he said.

The beta is downloadable here. The general release of the technology is planned for the end of this year and will work with Microsoft's Visual Web Developer 2005 Express Edition and free Web development IDE as well as with Visual Studio 2005.