InfoWorld’s Peter Wayner wrote an good overview of the most popular open-source toolkits, including a helpful screencast about each. Specifically, he covers:
* [Dojo][Dojo] _([screencast][Dojo screencast])_
* [Google Web Toolkit (GWT)][GWT] _([screencast][GWT screencast])_
* [Microsoft Atlas][Atlas] _([screencast][YUI screencast])_
* [Rico][Rico] _([screencast][Rico screencast])_
* [Yahoo! User Interface Library (YUI)][YUI] _([screencast][YUI screencast])_
* [Zimbra Kabuki Ajax Toolkit][Kabuki] _([screencast][Kabuki screencast])_
Which to use? Well, GWT is dependent on Java, which makes it a **non-starter** for everyone I know. Atlas (not surprisingly?) **doesn’t play well with others** — there are Firefox or Safari compability issues, and although the _client_ part is technology-agnostic, the _server_ part is ASP.NET. Rico is neat, but less complete. Kabuki looks interesting, but it’s also missing interesting features.
That leaves us with **[Dojo][Dojo]** and **[YUI][YUI]**. You can’t go wrong with either, and any time you spend learning them now will pay off for years to come. I believe these two toolkits will evolve into the dominant frameworks for standards-based client development.
* [InfoWorld: Surveying open-source AJAX toolkits][InfoWorld]
[Dojo screencast]: http://www.infoworld.com/video/archives/2006/07/screencast_ajax.html
[GWT screencast]: http://www.infoworld.com/video/archives/2006/07/screencast_goog.html
[Atlas screencast]: http://weblog.infoworld.com/udell/screenroom/atlas_flv.html
[Rico screencast]: http://www.infoworld.com/video/archives/2006/07/screencast_rico.html
[YUI screencast]: http://www.infoworld.com/video/archives/2006/07/screencast_yaho.html
[Kabuki screencast]: http://www.infoworld.com/video/archives/2006/07/screencast_zimb.html