None of these are Standard ML! There are people who prefer SML for various reasons.

Somewhat unexpectedly, there is in fact already a very good SML-to-browser solution, namely the unfortunately named SMLtoJs: https://github.com/melsman/mlkit/blob/master/README_SMLTOJS....

It's from 2011 and so predates most other Javascript-targeting languages. It's unfortunate it never got any traction.

SOSML [0] came out recently, written in TypeScript and sporting an online interpreter. Then there's this prominent SML-er's JavaScript backend for Moscow ML [1]. And Andreas Rossberg's HaMLet [2] also has a JavaScript backend.

[0] https://github.com/SOSML/SOSML

[1] https://github.com/kfl/mosml-js

[2] https://people.mpi-sws.org/~rossberg/hamlet/

There is also F# Fable[0] compiler that compiles F# to JS. I would say its more ML like, syntax wise (excluding bucklescript ofc).

[0] https://fable.io/

I was going to point out the same; if you can get your ML fix from F#, definitely look Fable up -- it's nothing but surprised me with how well polished it is.

Facebook's part is actually just the syntax of ReasonML, the actual ML-Javascript-compiler is Bucklescript from Bloomberg.

BuckleScript’s author works for Facebook for years now.

Reason is just a syntax frontend. You should be linking to BuckleScript instead.