F# is excellent. It’s tooling, ecosystem, and compile times are the reason I don’t use it. I learned it alongside OCaml, and OCaml’s compilation speed spoiled me.

It is indeed a shame that F# never became a first class citizen.

Lots of this, especially the tooling and ecosystem, improved considerably in the last couple of years.

OCaml is a great language, as are others in the ML family. Isabelle is the first language that has introduced the |> pipe character, I think.