regex101 : Free PCRE-based regular expression debugger with real time explanation, error detection and highlighting.
CSS Reference : Learn by example: cssreference.io is a free visual guide to CSS. It features the most popular properties, and explains them with illustrated and anima...
Eloquent JavaScript : Eloquent JavaScript is a book providing an introduction to the JavaScript programming language and programming in general.
Stack Overflow : Stack Overflow is a question and answer site for professional and enthusiast programmers.
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...