The ACME category on Hackage is for joke packages. The name “Acme” is a reference to the name of the company from which Wile E. Coyote obtains dangerous contraptions that always backfire.
Examples of ACME packages
acme-everything has a dependency on every other package in Hackage.
acme-cofunctor defines the
Cofunctor class. This is a joke because “cofunctor” would be “the dual of functor,” but it turns out that the dual of functor is exactly the same as functor itself, Another way to say this is that functor is self-dual. so this package is useless
Cofunctor is completely redundant to