This package only exports definitions from the "mtl" and "transformers" libraries. Unlike every module of "mtl" it does not reexport 'Control.Monad' and 'Control.Monad.Fix'.
In combination with the <http://hackage.haskell.org/package/base-prelude "base-prelude"> library, this should give you a quite rich prelude.
The '2.*' versions are restricted by the feature set of 'mtl-2.2' and 'transformers-0.4', however they provide support for newer versions of those libraries as well.