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...
The CMS Matrix : CMSmatrix lets you easily compare the features in over 1200 content management system products. Check the boxes next to the software you're interested...
regex101 : Free PCRE-based regular expression debugger with real time explanation, error detection and highlighting.
I Love Typography : I Love Typography, devoted to fonts, typefaces and all things typographical.
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).