Reflex is a reactive UI library that is heavily inspired by (pretty much is a port of) elm and it's amazingly simple yet powerful architecture where "flux" (in react terms) is simply a byproduct of a pattern. In order to keep a major attraction of elm — algebraic data types & type safety — the library uses flow, a static type checker, that being said it's your call whether you want to use flow yourself or just happer a pure JS either way this library has things to offer.
Library is authored as pure ES modules and can be used with import syntax.
import * as Reflex from "//reflex.hashbase.io/lib.js"