Great set of CSS hover effects - iHover
PHPVerbalExpressions - the easiest way to start with Regular Expressions. Write it in OOP way
$regex=new VerbalExpressions;
$regex ->startOfLine()
->then("http")
->maybe("s")
->then("://")
->maybe("www.")
->anythingBut(" ")
->endOfLine();
$regex->test("http://d.com")
A lot of implementations on other languages exist
Great set of CSS hover effects - iHover
PHPOffice a set o pure PHP libraries that allow to read, write and create - PHPWord, PHPExcel, PHPVisio, PHPProject, PHPPowerPoint
gitbook - command line utility for generating books and exercises using GitHub/Git and Markdown. Here is example book
uberVU / grid - drag and drop js library for two-dimensional, resizable and responsive lists
A simple overlay instructions for site interface with jQuery plugin Chardin.js