It's a crossword puzzle where you need to fill in the hexes with character sequences, so that they match the regular expressions listed around the edges.
The individual clues will turn bold purplebold green when satisfied, orangered when not, and underlined when active.
Note that the regex must be a full match, and empty cells are treated as spaces.
Double click a rule to edit it. When finished, press 'enter'.
  Size:   Name:   Author:   

Original puzzle written by Dan Gulotta for the 2013 MIT Mystery Hunt.
Select a puzzle:

Javascript implementation by Jimb Esser. Source code available on GitHub, fork and add your own puzzles!
Solution available here.
Best viewed in Google Chrome or Firefox. Your work should be saved if you refresh the page or come back later.