Scripts

Ajax Cookbook
A web site devoted to publishing small, reusable snippets of JavaScript, HTML, and CSS that are generally useful to developers of Ajax web sites.
http://ajaxcookbook.org/

AJAX Crawler
Provides a collection of scripts using JQuery or Prototype/Script.aculo.us.
http://www.ajaxcrawler.com/

Ajax Daddy
Offers a collection of scripts using Ajax.
http://www.ajaxdaddy.com/

Ajax F1
Provides a collection of Ajax scripts to be implemented on a website.
http://www.ajaxf1.com

CKFinder
AJAX based file manager provided by FCKeditor developers. [Commercial]
http://www.ckfinder.com

DHX Ajax Toolkit
Provides a set of cross-browser DHTML components for building Ajax-based web interfaces. Distributed under both GPL and commercial license.
http://dhtmlx.com

EJS TreeGrid
Provides a component to show data in a treegrid.
http://www.treegrid.com

Free ajax scripts & tutorials
A collection of free ajax scripts and tutorials.
http://freeajaxscripts.net

Google AJAXSLT
Provides an implementation of XSL-T in JavaScript for AJAX applications. Includes links for downloading.
http://goog-ajaxslt.sourceforge.net/

Hot! Ajax
Provides a collection of jQuery and mootools plugins.
http://www.hotajax.org

JavaScript Spell Check
Provides a non-free multilingual spellchecker written with JavaScript an Ajax functionnalities.
http://www.javascriptspellcheck.com

JSLog
Lightweight ajax logger. takes the place of alert() boxes for AJAX and DHTML applications.
http://earthcode.com/blog/2005/12/jslog.html

KFM - Kae's File Manager
An Ajax file manager for PHP, which may be used stand-alone, or as a plugin for a rich text editor.
http://kfm.verens.com/

miniAJAX
A showroom of nice looking simple downloadable DHTML and AJAX scripts.
http://www.miniajax.com

Rialto
Provices a cross browser javascript widgets library. Because it is technology agnostic it can be encapsulated in JSP, JSF, .Net or PHP graphic components.
http://rialto.application-servers.com

Sajax
An open source XMLHTTPRequest toolkit with PHP, Perl, and Python backends.
http://www.modernmethod.com/sajax/

Xajax
Offers an open source PHP class library that allows to create Ajax applications using HTML, CSS, JavaScript, and PHP.
http://www.xajaxproject.org/