Online Regular Expression Testing
Regular expressions are an incredibly powerful tool, but can be rather tricky to get exactly right. This is a website that I wrote so I could quickly and easily test regular expressions during development.
Pick which language you are using to process regular expressions:
The original version was Java-based. No need to use it instead of the Java one above, but a lot of links go directly to it:
One last thing
Some people, when confronted with a problem, think “I know, I’ll use regular expressions.” Now they have two problems.
-- Jamie Zawinski in comp.lang.emacs.
-- Jamie Zawinski in comp.lang.emacs.