JavaScript module types

The following info is useful when you wish to use modern JavaScript tooling outside of a build system.

For instance I wanted to use a bundled React application in a static website not created using NPM.

Great account by Julia Evans.

In essence there are three main module formats:

  • CommonJS

    • Native Node JS module system using require() and module.exports()

  • ESModules

    • The defacto standard that works in both the browser and Node.js

  • AMD

    • A browser-friendly version of CommonJS since superseded by ESModules

Then there is UMD, Universal Module Definition. This is a wrapper that combines compatibility for multiple module systems and works with AMD, CommonJS, as well as global variables.

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