> The difference is that with Haskell or Erlang you get hard guarantees about side effects, but access to imperative libraries is very difficult. In my experie

> The difference is that with Haskell or Erlang you get hard guarantees about side effects, but access to imperative libraries is very difficult. In my experience creating Haskell bindings to say imperative c libraries is pretty easy. What imperative libraries have been hard to access for you personally?