My Elm dev environment with hot-loading (i.e. state is retained as you edit your code, uses https://github.com/fluxxu/elm-hot-loader). Like elm-community/elm-webpack-starter but using Webpack 3. I Use this daily for professional work.
With npm
$ npm install
$ npm run dev
With yarn
$ yarn install
$ yarn dev
Open http://localhost:3000 and start modifying the code in /src.
Build production assets with:
npm run prod
Prefer Gulp? See also my Gulp-based dev environment.