Webpack Chunking. Example from Megatome: React/Webpack starter. https://github.com/Levelmoney/generator-megatome/blob/master/generators/app/templates/_webpack.config.js

webpack.config.js

var globals = {
  React: 'react',
  ReactDom: 'react-dom',
  ReactRouter: 'react-router'
}
...

{
  entry: {
    app: ['./src/bootstrap.js'],
    libs: Object.keys(globals).map(function(k){ return globals[k]; })
  },

  output: {
    chunkFilename: "[name].js",
    filename: "[name].js"
  },

  module:{
    loaders: [{
      /* convert all source files */
      test: /\.(js|jsx)$/,
      include: [/src/,/bower_components/],
      exclude: [/(node_modules)/],
      loader: 'babel?plugins[]=transform-runtime&presets[]=es2015&presets[]=stage-0&presets[]=react&cacheDirectory=true',
    }]
  },
}

...

function updateLibs(config, options) {
  if(options.commonsChunk) {
    config.plugins.push(new webpack.optimize.CommonsChunkPlugin('libs', "libs.js"));
  }
}