The Par monad(s) offer an alternative parallel programming API to that
provided by the 'parallel' package. A Par monad allows the simple
description of parallel computations, and can be used to add parallelism
to pure Haskell code. The basic API is straightforward: a Par monad
supports forking and simple communication in terms of IVars. This module
is an interface module only. It provides a number of type clasess, but
not an implementation. The type classes separate different levels of Par
functionality.

WWW: https://github.com/simonmar/monad-par