Infragistics is ASP.NET AJAX (ATLAS) Compatible
http://www.infragistics.com/corporate/pressreleases/aspnet-ajax-compatibility.aspx
Tony will likely follow up with more information in his blog next week when he gets back from his honeymoon.
Also see this: http://www.infragistics.com/hot/aspnet-ajax-support.aspx for more information on our support.
Currently listening to Not Going Home by The Elected from the album Sun, Sun, Sun