Haskell monad transformer library for GHC

 MTL is a monad transformer library, inspired by the paper "Functional
 Programming with Overloading and Higher-Order Polymorphism",
 by Mark P Jones (<http://www.cse.ogi.edu/~mpj/>), Advanced School
 of Functional Programming, 1995.
 .
 This package provides a library for the Haskell programming language.
 See http://www.haskell.org/ for more information on Haskell.