ComposeJS is a lightweight JavaScript library for object composition ComposeJS is robust object composition built on native JavaScript mechanisms. ComposeJS is lightweight (3K minified, 1K gzipped) JavaScript module based on the philosophy that JavaScript's powerful composition mechanisms, including prototype inheritance, closures, and object literals should be embraced, not contorted into an emulation of classes from other languages. It is designed to be secure, to-the-metal fast, simple, and easy to use. ComposeJS builds on some of the best concepts from mixins, (traits)[], and deterministic multiple inheritance. ComposeJS assists in composing constructors and instances, providing shorthand and robustness for best practice JavaScript. In fact, in the documentation equivalent JavaScript code is provided to show exactly what is happening.