SQL Injection Cheat Sheet : Samples are provided to allow reader to get basic idea of a potential SQL Injection attack and almost every section includes a brief information about...
idiomatic-css : Principles of writing consistent, idiomatic CSS
PHP Coding Standard Generator : The goal of this site is to enable you do very quickly create and maintain your own coding standard.
PHP Mess Detector rule sets files and PHP Code Sn...
Stack Overflow : Stack Overflow is a question and answer site for professional and enthusiast programmers.
Linked Data : This site exists to provide a home for, or pointers to, resources from across the Linked Data community.
This is a collection of known design patterns and some sample code how to implement them in PHP. Every pattern has a small list of examples (most of them from Zend Framework, Symfony2 or Doctrine2 as I'm most familiar with this software).