Purpose

This library is intended to be a drop-in replacement to forkIO, with the difference that you can specify well-known strategies on how to deal with errors gracefully and reliably. A difference with vanilla forkIO is that you'll need to do a bit more of setup specifying supervision rules, and also you need to pass along a reference of a supervisor for every thread you fork.

Background

As time progresses, I've come to love developing concurrent applications in Haskell, its API (STM, MVars, etc.) and light threading RTS bring a lot to the table. There is another technology that is more famous than Haskell in regards to concurrency, and that is Erlang, more specifically its OTP library.

If you wonder why that is, you may need to look into the OTP library design, actors systems (in general) provide an architecture that enables applications to be tolerant to failure through the enforcement of communication via message passing and by making use of a critical infrastructure piece called a Supervisor.

After trying to replicate Erlang's behavior on Haskell applications by using the distributed-process library (a clone of OTP), and after implementing several (disposable) iterations of actor systems in Haskell, I've settled with just this library, one that provides a simple Supervisor API.