There are a few libraries out there; Async_parallel is one: https://blogs.janestreet.com/async-parallel/ https://blogs.janestreet.com/async-parallel/ Lwt also

There are a few libraries out there; Async_parallel is one: https://blogs.janestreet.com/async-parallel/ https://blogs.janestreet.com/async-parallel/ Lwt also has the Release framework which does multiprocess: https://github.com/andrenth/release https://github.com/andrenth/release and more if you search through OPAM.