What it's sorely missing right now is higher quality documentation output. Currently, it's hard to navigate the generated documentation (e.g., no search bar), it's not held in a centralized online location, and it doesn't do a great job dealing with complex module/functor hierarchies (especially in the presence of destructive substitution).
Unfortunately, much of what I described above doesn't come out of the box. To fix this, the OCaml community is seeking to emulate Rust's cargo tool via the development of the ocaml-platform: http://ocamllabs.io/doc/platform.html
An aside: I didn't know Java had good tooling. I know it recently gained a good REPL. But what is the official package manager, and where is the centralized repository for packages?