If you're using Babel to transpile your ES6/7 code and Rollup to generate a standalone bundle, you have a couple of options: * run the code through Babel first, being careful to exclude the module transformer, or * run the code through Rollup first, and *then* pass it to Babel.

Both approaches have disadvantages. Using Rollup with rollup-plugin-babel makes the process far easier.

Node.js is an event-based server-side JavaScript engine.