ASP.NET Ajax
In case you haven't heard yet, ASP.NET Ajax 1.0 has been released! This is fully supported by Microsoft. It's great to see the culmination of effort by the ASP.NET team.
http://weblogs.asp.net/scottgu/archive/2007/01/23/asp-net-ajax-1-0-released.aspx
The great news about ASP.NET Ajax library is that it caters to "both" kinds of developers- Client Centric, as well as Server Centric.
Client centric developers can very easily plug in to the javascript library. For those of you who have been writing Javascript and remember technologies like remote scripting, the web service behavior, etc. you can now tap into a very powerful library that is cross browser compatible and abstracts usage of making remote rpc calls.
The great news for traditional ASP.NET developers, as well as those who despise writing Javascript, is that EVERYONE can now easily harness the power of rich client web applications. The ASP.NET team has really made it painless to add this type of functionality. If you want to be able to do cool things like automatically update a portion of a web browser without visibly posting back the entire page, you can easily add ASP.NET Ajax to your EXISTING web application with the UpdatePanel control. That is the great news about this- you're not re-writing your application to implement Ajax. In addition, the ASP.NET control toolkit (http://ajax.asp.net/ajaxtoolkit/) integrates with the ASP.NET Ajax Library and provides server centric developers with some great out of the box controls, from drop down extenders (pick a state, get back a list of cities from a web services w/o having to preload everything) to adding cool DHTML code (such as draggable panels and animations). It's shared source and hosted on CodePlex.
Hope you enjoy this release. Now go and make your apps ajax'd!!