AJAX

Easy Ajax with jQuery
1001 + Ajax/Javascript/Dhtml examples and demos to download
Mini Ajax : Simple DHTML & AJAX Scripts
Ajax: A New Approach to Web Applications (Adaptive Path)
AJAX:Getting Started (Mozilla)
AJAX Tutorial (w3schools)
A Simpler AJAX Path (ONLamp)
Lightview
KFM - Kae's File Manager - an Ajax file browser
mooTools
jqzoom : jqzoom is an handy script to magnify your galleries.Based on jQuery.

Content Management

DRUPAL
Shopdaddy

CSS

Styling the button element with sliding doors | Filament Group, Inc.
Dolphin | 13styles CSS Menus

Debugging

Firebug :: Firefox Add-ons

Frameworks

CakePHP
CodeIgniter
Symfony

Graphics

imgAreaSelect examples - odyniec.net
dafont.com : Archive of freely downloadable fonts. Browse by alphabetical listing, by style, by author or by popularity.
FavIcon from Pics -- favicon.ico for your website : Free and easy to use online tool that can create favicon (.ico) images for browser address bars, favorites and tabs, from pictures, logos and other graphics.

Inline Editors

AJAX In Place Rich Editor
NicEdit
jQuery FCKEditor Plugin v1.21

jQuery

jQuery Collapsible Menu
Flexigrid
jQuery Air
CSS Dock Menu
Nested Sortable Widget Demo
Nested Sortables Demo
Using jQuery with Other Libraries - jQuery JavaScript Library
jQuery File Tree Demo
240 plugins jquery : sastgroup.com
SimpleModal
jQuery UI Accordion
Slide Demo - Fixed Drawer
50+ Amazing Jquery Examples- Part1
FastFind Menu
jQuery validation plug-in - main dem

Open Source

The Open CD

OpenID Resources

OpenID.net
MyOpenID.com
ClaimID.com
OpenID Yahoo
Twit.tv

PHP.NET

Javascript Remote Scripting on Sourceforge
Tizag.com Tutorial

PDF Resources

FAST PDF
PDF ONLINE

Regular Expressions

Tudelft Regular Expression Tutorial

RSS Information

RSS Specifications

CSS

 Styling the button element with sliding doors | Filament Group, Inc.

Other:

Geany : Screenshots   This is the Notepad++ equivalent for Ubuntu. 
Google App Engine - Google Code
Statbrain.com - Tells you how many visitors any site really has Free service that reveals the number of visitors that any website has.

Microsoft IE

Download details: Internet Explorer Developer Toolbar
Download details: Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats Open, edit, and save documents, workbooks, and presentations in the file formats new to Microsoft Office Word, Excel, and PowerPoint 2007.

Business  

Panasonic KX-TA, KX-TAW, KX-TD, KXT Phone Systems
SourceForge.net: Timesheet : Tools to manage timesheets online with PHP and MySQL. Good for maintenance plans or generally not getting into arguments over billing details

Humor  

YouTube - Boiler room - How to close - Classic Ben Affleck demonstrates how to push a sale without mercy.
YouTube - Suckers Trailer for "Suckers". A tutorial in how to sell anything to anyone and still sleep at night ... sort of.