by Isabella Leandersson, Thomas Leonard, and Anil Madhavapeddy on Mar 20th, 2024The OCaml 5 update brought much-anticipated support for programming on multiple cores. It also introduced support for concurrency via effect handlers – one of the first mainstream languages to do so. This significant update has had profound performance and UX implications, propelling OCaml into new areas of software development. At the core of this leap forward is the ambition to craft a modern, direct-style I/O stac...