If you're an Introscope Power-User, you're bound to have encountered "the regexp problem". You know, you're trying to write that special regexp that will match this string but get rid of these ones, and you think you have it working, but really not and you can't figure out why.
The good people on the Internet have designed a pretty darn good solution: http://www.regexr.com/
This should put a stop to regexp abuse all across the globe!
PS: No regexps have been harmed during my trials.