My last startup was a company called IMSafer http://www.imsafer.com http://www.imsafer.com. We built an entire product around extensive and extremely complicate

My last startup was a company called IMSafer http://www.imsafer.com http://www.imsafer.com. We built an entire product around extensive and extremely complicated regex's to find patterns of language that might indicate a sexual predator going after a kid. The only tool that was useful to me was Regex Buddy http://www.regexbuddy.com http://www.regexbuddy.com. Downside is that it doesn't run on the Mac, but I'm telling you for creating and debugging regular expressions it is THE tool to use. We had to optimize not only for matching, but for performance and as you know if you write your regex's wrong, you can kill performance. Regex Buddy has a debug mode that lets you see all the steps taken by the regex and lets you find ways to optimize. Highly recommended.