Four more AJAX / JavaScript frameworks and code

SimpleJS: A javascript library simple and light proposing functions ready with the use to facilitate the exploitation of ajax.

Script.aculo.us: provides you with easy-to-use, cross-browser user interface JavaScript libraries to make your web sites and web applications fly.

Prototype: Is a JavaScrip framwork that aims to ease development of dynamic web applications. Featuring a unique, easy-to-use toolkit for class-driven development and the nicest Ajax library around, Prototype is quickly becoming the codebase of choice for web application developers everywhere.

ASP.NET AJAX: A free framework for quickly creating a new generation of more efficient, more interactive and highly-personalized Web experiences that work across all the most popular browsers.

Also, don't forget to check out what the big guys like Yahoo! and Google offer.