This is QuickCheck 2, a library for random testing of program properties.

Install it in the usual way:

$ cabal install

The quickcheck-instances [1] companion package provides instances for types in
Haskell Platform packages at the cost of additional dependencies.

The make-hugs script makes a Hugs-compatible version of QuickCheck.
It may also be useful for other non-GHC implementations.

[1]: http://hackage.haskell.org/package/quickcheck-instances