If you know regular expressions, you might find this to be geek fun. A friend of mine posted this, without a solution, but once I started working it, it seemed put together well enough it was likely solvable. Eventually I did solve it, but not before coding up a web interface for making it easier to interact with, which I recommend using if you are going to try this out. Or just print it out.
It's actually quite impressive of a puzzle in it's own right. It must have taken a lot of work to create. I learned later that the puzzle was originally part of the 2013 MIT Mystery Puzzle Hunt created by Dan Gulotta from an idea by Palmer Mebane. I've heard amazing things about these events, this doesn't surprise me.
My puzzle web interface was also a bit of fun to smash together. I wanted the puzzle to be rotatable, but for the input boxes to stay upright through the rotation. I also wanted the browser to verify the regexps for me as I went along. Getting the hex cells to work in CSS took a bit of doing, and I admit it's not very cleanly done.
Code has been uploaded to github if anyone wants to play with it: Gregable/regexp-puzzle