A module allowing you to test your PCRE with PHP in a very efficient way

Regular Expression Editor
Free
Offline
http://www.waterproof.fr/products/RegExpEditor/

The regular expression editor is a module allowing you to test your PCRE with PHP in a very efficient way.
It wraps preg_match, preg_match_all, preg_replace and preg_quote functions, and offer a visual GUI where you can tweak your regular expression easily.