Question to the Haskell experts here.

Is Haskell more academic in nature or used heavily in Production environments?

Is there an application sweet spot/domain (say Artificial Intelligence/Machine Learning, etc) where it shines over using other languages (I am not talking about software/language architectural issues like type systems or such)?

I have no experience with Haskell but do use functional languages such as Erlang/Elixir on and off.

We use Haskell in production at lumi.com for our backend/API. We've found it very productive and easy to maintain.

React, HapiJS, RethinkDB, Node and Haskell. That might be the coolest stack ever. Do you have any FOSS project on Github?

No projects under the Lumi name yet, but our team contributes to many FOSS projects and also have their own interesting projects such as Purescript by Phil Freeman who recently joined the team: https://github.com/purescript/purescript