100 Days of Wordplay - 100 Day Project - 100 mini crossword puzzles
RegExr - RegExr.com is an online tool to learn, build, and test Regular Expressions.
Crossroad - Don’t chase after your friends’ pictures anymore
rubular - A ruby based regular expression editor
Regex Crossword - Welcome to the fantastic world of nerdy regex fun!
RegEx Generator - RegEx Generator is a simple-to-use application that comes with the brilliance of intuitive regex and is also helping you out to test the regex.