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...
regex101 : Free PCRE-based regular expression debugger with real time explanation, error detection and highlighting.
Kraken Framework : Kraken is the first and only multi-processed, multi-threaded, fault-tolerant framework for PHP. It has been written to provide easy and reliable API f...
idiomatic.js : Principles of Writing Consistent, Idiomatic JavaScript
schema.org : This site provides a collection of schemas that webmasters can use to markup HTML pages in ways recognized by major search providers, and that can als...
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).