The Eighth Annual ICFP Programming Contest
Jun 24-27, Jul 9-10.
"This year's competition rewards programmers who can plan ahead. As before, we'll announce a problem and give you three days to solve it. Two weeks later, we'll announce a change to the problem specification and give you one day to adapt your program to the new spec. And you guessed it: the second half will be worth considerably more than the first."