haskell

I keep hearing about how this is a great language and how it will enlighten you, but aside from xmonad, I have yet to see any useful l software produced in it.

I get that functional programming makes some things easier, but how come haskell has no real code in it?

>>14
Imagine you've implemented a large program in a purely functional way. All the data is properly threaded in and out of functions, and there are no truly destructive updates to speak of.
Go on
Now pick the two lowest-level and most isolated functions in the entire codebase. They're used all over the place, but are never called from the same modules.
Go ooon
Now make these dependent on each other: function A behaves differently depending on the number of times function B has been called and vice-versa.
Wait, what? I wrote a large program in a purely functional way but it isn't purely functional? Clearly the person who can actually achieve this is a genius and should be given infinite money for further R&D.