> Neither beautiful nor a visualization really.
This is the least helpful thing I can imagine. "Here's a beautiful regex visualizier" "LOL NO IT'S NOT". Geez.
There's useless pedants like this all over the Internet. You should probably wear a hat.
I'd agree if this were the top two comments without many disagreeing replies or down-votes.
I see this comment in down-voted grey, somewhere way down the page and assume a lack of social skills, bad-morning-before-coffee-grumps.
Or simply Internet Asshat Background Radiation, it's everywhere. Legends say you can trace its echos back to the First Flame from which the Internet was born.
Quite useful to show junior devs who are usually afraid of RegExp. Example from jQuery/Sizzle's: http://cl.ly/image/321F0E2B222o (^ and $ removed since it's failing to parse)
For the uninitiated, there's an isomorphic relationship between regular expressions (not PCREs which are way more complicated) and finite state automata proving that if you have a regexp you can generate a FSA for it, and visa versa.
What we have here is a system that generates a graph of the finite state automaton for any given regular expression.
Neat project, misleading headline.
edit: let me add more constructive comments. What is useful about things like rubular (http://rubular.com/ ) is the ability to see how a Regexp behaves with a given input. Where a finite state chart can be useful is giving users a better impression of the internal workings of a particular regular expression. Where rubular can indicate where a match can be found, it would be cool to have a tool like this if you can show the path a particular input would take (and possibly fail out on) through a given regular expression.