Essentially, OCaml 5.0 is OCaml 4.14 with a fully rewritten runtime which introduces support for parallelism (no more global runtime lock) and an experimental version of algebraic effects.
> no more global runtime lock
Perhaps Python devs should consider transpiling to OCaml ;)
The naming potential is incredible at least.
Parallelism [1] and native-support for concurrency through effect handlers [2].