The developers point out that ReScript has the power of JS and the advantages of a typed language but without all of the types of JS to manage. It is possible to install via npm or npx. But you can use the JS libraries. Phew. For the build part, we have Ninja which works like make.
ReScript for typing is based on the OCAML system. Even the toolchain uses elements of OCAML.
If ReScript doesn’t interest you, try ReasonML
For more information: https://rescript-lang.org/docs/manual/latest/introduction