I am increasingly convinced that Haskell only exists so that people who know it can pat themselves on the back for being wonderful.
With the exception of pandoc, I don't recall seeing anything particularly impressive from the Haskell camp.
(Btw, this, actual stuff people use, is how I measure programming languages -- this metric takes into account communities, libraries, practical issues, etc all together, and ties them with practical results. It's my version of "let the market decide").
You may want to check out Warp [1]. Another quite popular haskell project you may have heard about is this compiler some people use... is called ghc :) [2]