I am very excited not only for the native parallelism that's coming in 5.0 but also about the effect handlers! I am sure many others are looking to start creating very interesting things with them, e.g. Rust-alike async capabilities or Erlang's preemptive green threads / actors runtime.
More info: https://discuss.ocaml.org/t/multicore-ocaml-september-2021-e...
Really looking forward to what the community will build with OCaml 5.00! IMO it will shoot the language straight into the mainstream and I can't wait. OCaml is applicable for like 90% what's out there, including as a Python replacement. And its syntax is often much terser than Rust (although the higher-level typing constructs can be confusing to read).
After that, all that's left is a tool like Elixir's mix or Rust's cargo and the language is basically not only in the 21st century but much farther than many others! Looking forward to it.
This so much. Mix is so pleasant to work with, but getting an OCaml project off the ground requires messing with dune + esy if you want consistent and isolated package management. It's a massive pain.