haskell Monad classes using type families, with instances for various monad transformers, inspired by the paper /Functional Programming with Overloading and Higher-Order Polymorphism/, by Mark P Jones, in /Advanced School of Functional Programming/, 1995 (<http://web.cecs.pdx.edu/~mpj/pubs/springschool.html>). This package is almost a compatible replacement for the @mtl-tf@ package.