I am a asp.net developer and I have been keeping track of Atlas. It is good to know there are several Ajax toolkits that we can use today:

• Prototype: http://prototype.conio.net/
• Script.acuto.us: http://script.aculo.us/
• Rico: http://openrico.org/
• Dojo: http://www.dojotoolkit.com/
• Google Web Toolkit: http://code.google.com/webtoolkit/
• Yahoo Ajax Library: http://developer.yahoo.com/yui/
• BorgWorx (formerly Ajax.Net): http://borgworx.com/
• Also see the list on Ajaxian site: http://ajaxian.com/resources/