Neocaml 0.9 (a collection of #Emacs major modes for programming in #OCaml) is out with updates for OCaml 5.5, many top-level integration improvements and built-in completion for Opam and Dune https://github.com/bbatsov/neocaml/releases/tag/v0.9.0

It's a pretty cool release and I hope you'll enjoy it!