regexp – My Bookmarks

RegexOne – Learn regular expressions with interactive examples

http://regexone.com/

RegExr: Learn, Build, & Test RegEx

http://www.regexr.com/

RegExr: Online Regular Expression Testing Tool

http://www.gskinner.com/RegExr/

Regular-Expressions.info – Regex Tutorial, Examples and Reference – Regexp Patterns

http://www.regular-expressions.info/index.html

Regex Tutorial – Word Boundaries

http://www.regular-expressions.info/wordboundaries.html

Programmer’s Guide to Regular Expressions

http://www.javascriptkit.com/javatutors/redev.shtml