Question: Do you know any online problem sets or contests that accept solutions in Haskell? I know only [El Judge](http://acm.mipt.ru/twiki/bin/view/ELJudge/WebHome), but unfortunately it has some problems with ghc, so any Haskell problem is rejected with "memory limit" resolution.

Answer: 
[Sphere Online Judge (SPOJ)](http://www.spoj.pl)

It uses ghc 6.10.4 compiler.
[Facebook Puzzles](http://www.facebook.com/careers/puzzles.php) (GHC Haskell 6.8.2)