OCaml 5.0 is out. Now it supports multicore.

published on 2022/12/17

The highlight of this new major version of OCaml is the long-awaited runtime support for shared memory parallelism 309 and effect handlers 534.

This multicore support is the culmination of more than 8 years of effort, and required a full rewrite of the OCaml runtime environment. Consequently, OCaml 5.0.0 is expected to be a more experimental version of OCaml than the usual OCaml releases.

In this release, the native compiler only supports the x86-64 and arm64 architectures. In terms of operating systems, Linux, the BSDs, macOS and mingw64 on Windows are supported.


This is a huge achievement to have multicore support finally land in this amazing language and ecosystem. Congratulation to everyone involved.