You give us a regex and we'll show you what it matches.
Why do this? Every other "regex tester" site out there simply shows you how the regex you are working on matches (or more likely fails to match) some example text you give it. Yeah, you've been doing this for hours with your own tools already! Sometimes, you'd really like someone to just show you examples of what your regex actually matches and consider changes based on what you see. You've got an extra slash and a missing star. That's why we do this.
Take a sneek peek at the new oh-so fragile prototype version!