I'm happy
with OCamlMakefile.
I have to say that I find it truly charming if not
flattering that people are still using my ancient
OCamlMakefile (which, btw., is now more than 20 years old!).
Seriously, I think that every OCaml developer should switch
to OPAM + Dune at this point. The ease of developing,
contributing to, packaging, releasing, and using OCaml
software has improved dramatically over the years, especially
with these tools. I'm generally reluctant to jump on the next
build tool or package manager, but my expectation is that
these tools will stay around for many years to come.
--