Node and Elm v0.18 should be installed on your system. Then:
$ npm install
This will recompile and reload your app in the browser evertyme you update a
.elm file. App is available at localhost:8000/.
$ npm run live
There's also very convenient debug version with the Elm debugger:
$ npm run debug
$ npm run publish-to-gh-pages
$ npm test
To have tests automatically run on each file change:
$ npm tdd