A bit of background To quote the official docs: Melange is a backend for the OCaml compiler that emits JavaScript. Melange strives to provide the best integration with both the OCaml and JavaScript ecosystems. Basically, Melange lets you generate JS code from OCaml code. Reason (aka ReasonML) is an alternative syntax for OCaml that looks more like JS. Reason React are Reason bindings to React so t