PHP

apache friends - xampp

PHP: Hypertext Preprocessor

PHP: PHP Manual - Manual

Zend Developer Zone

PHP Security Consortium

Essential PHP Security by Chris Shiflett

Top 7 PHP Security Blunders

PHP Script and Programs :: Hot Scripts

PHP Scripts

PHP classes

Iranphp

MySQL

MySQL :: The world's most popular open source database

PHP: MySQL - Manual

phpmyadmin

MySQL-Front

Ajax

Ext - A foundation you can build on

jQuery: The Write Less, Do More, JavaScript Library

mootools: A Compact Javascript Framework

Ajax/Javascript/Dhtml examples and demos to download

Ajax Code Examples, Free Ajax Scripts, Ajax Downloads

Ajaxian

SEO

Alexa the Web Information Company

Webmaster Tools & SEO Tools

Search Engine Optimization

Search Engine Optimization, Google Optimization - SEO Chat

SEO/SEM optimization & SEO news | SeekAndHit Hrvatska

Search Engine Optimisation SEO & Search Engine Marketing

Seo Administrator - seo tools, seo software