ghc-proofs (hackage): Often when writing Haskel code, one would like to prove things about the code.  A good example is writing an Applicative or Monad instance: there are equation that should hold, and checking them manually is tedious.  Wouldn’t it be nice if the compiler could check them for us? With this plugin, he can! (At least in certain simple cases – for everything else, you have to use a more dedicated solution.)  See the documentation in GHC.Proof or the project webpage for more examples and more information.
Keywords: compiler-plugin|formal-methods|library|mit