-This takes an image, divides it into a grid, and then randomly shuffles
-the squares around as if it was one of those annoying ``16-puzzle''
-games, where there is a grid of squares, one of which is missing.
-I hate trying to solve those puzzles, but watching one permute itself
-is more amusing. Written by Jamie Zawinski.
+This takes an image, divides it into a grid, and then randomly
+shuffles the squares around as if it was one of those "fifteen-puzzle"
+games where there is a grid of squares, one of which is missing.
+
+http://en.wikipedia.org/wiki/Fifteen_puzzle
+
+Written by Jamie Zawinski; 1994.