[Haskell-cafe] automatic Haskell indentations

Looking for automatic indentation of Haskell code I found the thread http://www.haskell.org/pipermail/haskell-cafe/2003-August/005000.html It ended up with many suggestions for manual formatting of code. I wonder if there is some tool which simply formats a Haskell program. A tool like 'indent' (or 'm3pp' for Modula-3) which processes data from stdin to stdout could be nicely integrated into NEdit.