The other matter of style is whether the order of the code matches the order in which the user interacts with it.
The three steps in user experience order:
first: a form to accept input,
second: a link to click
third: a printout of the input
Here are the orders used in code: Ruby+sinatra: third, first, second
arc version 1: third, second, first (original)
arc version 2: second, third, first (May 2009)
Haskell+custom: first, second, third
Interesting results, I think Haskell wins here. Though technically it fails the challenge (the arc version 2 example fails too) since the supporting library was written after the challenge was considered by the author of the example.