[dbaupp]

That's not a very good definition. It means that GHC-flavoured Haskell isn't functional: http://www.haskell.org/haskellwiki/Tail_recursion

[batterseapower]

I think you might have misinterpreted the contents of that page. As someone who has worked on GHC, I can assure you that it does perform tail call optimisation.

[dbaupp]

I believe I have. Thank you for correcting me.