The runtime aspects of the multicore runtime has been pretty stable.  Most of the effort currently is going into the algebraic effects extension that is used to map direct-style concurrency into multiple (parallel) cores: <a href="https:&#x2F;&#x2F;github.com&#x2F;ocamllabs&#x2F;ocaml-effects" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;ocamllabs&#x2F;ocaml-effects</a>