You can use the normal OCaml syntax with the main OCaml compiler and the js_of_ocaml compiler. If you just want something in the ecosystem that's boring and reliable these are almost certainly the way to go.
However, even Js_of_ocaml is suffering a slight complication :P There is the recent release of Brr https://erratique.ch/software/brr/doc/, a Js_of_ocaml library replacement (i.e. you keep the compiler but use this instead of the library that comes with Js_of_ocaml).
I heard good reviews of Brr, but haven't tried it myself yet. We will probably have a Brr full-stack example in Dream, eventually.
Personally, I currently use
- Dream on the server (an ancient version, didn't have time to keep up with Dream development in my own app!).
- Just plain JS and the JS ecosystem on the client.
- ReScript/Melange for compiling a couple files to JS from OCaml so that they can trivially interop with my mostly-JS client.