Some popular Ajax Toolkits

 Some popular Ajax Toolkits

Name	Client/Server	High/Low-level	Comments
Prototype (http://prototypejs.org)	Client	Low	Remodels and extends JavaScript following the Ruby scripting language. Many features for arrays, functions, XHR, DOM and forms.
Scriptaculous (http://script.aculo.us)	Client	High	Special effects, drag and drop, and widgets built on top of prototype.
dojo (http://dojotoolkit.org)	Client	Low-high	Comprehensive set of libraries covering everything from packaging & language features through Ajax to UI widgets.
Yahoo User Interface (YUI) (http://developer.yahoo.com/yui/)	Client	Low-high	Another comprehensive set of libraries covering many aspects of Ajax development.
Ext (http://extjs.com)	Client	High	Widget-based set of user interface components with Ajax support.
sarissa (http://sarissa.sf.net)	Client	Low	Rich library for working with XML, providing cross-browser XPath and XSLT.
Mochikit (http://mochikit.com)	Client	Low-high	General-purpose Ajax and DHTML library, inspired by Python.
jQuery (http://jquery.com)	Client	Low	Small, concise Ajax and DOM helper library.
MooTools (http://mootools.net)	Client	Low-high	Modular library covering everything from core classes to special effects. A promising newcomer.
Ruby on Rails (http://www.rubyonrails.org)	Server	Low-high	Primarily a server-side toolkit, but has first-rate support for Ajax, using Prototype and Scriptaculous. Allows large parts of the client tier to be written on the server, in Ruby.
GWT (http://code.google.com/webtoolkit)	Client	High	Java framework that allows Ajax client tier to be written in Java.
JSF (various vendors)	Server	High	Various JSF vendors have Ajax-enabled some of their components, again allowing some Ajax functionality without hand-writing JavaScript.