They are actively working on it (https://discuss.ocaml.org/t/multicore-ocaml-may-2020-update/5898 https://discuss.ocaml.org/t/multicore-ocaml-may-2020-update/..

They are actively working on it (https://discuss.ocaml.org/t/multicore-ocaml-may-2020-update/5898 https://discuss.ocaml.org/t/multicore-ocaml-may-2020-update/...) (HN discussion here, https://news.ycombinator.com/item?id=23380370 https://news.ycombinator.com/item?id=23380370).