mmmm.js

// index.js
module.exports = require('./Library/app');

// Source/app.js.es6
import from 'foo';
import from 'bar';

// Source/foo.js.es6
console.log('simple');

// Source/bar.coffee
more = require 'more'

// Source/more.coffee
console.log 'not so simple'

nnnn.sh

babel --out-dir 'Library' 'Source/*.es6'
coffee --compile --output 'Library' 'Source/*.coffee'