MuJS is a lightweight Javascript interpreter designed for embedding in other
software to extend them with scripting capabilities. It is written in portable
C and implements ECMAScript as specified by ECMA-262.

Why? Because V8, SpiderMonkey and JavaScriptCore are all too big and complex.
MuJS's focus is on small size, correctness and simplicity.

The interface for binding with native code is designed to be as simple as 
possible to use, and is similar to Lua. There is no need for interacting with 
byzantine C++ template mechanisms, or worry about marking and unmarking garbage 
collection roots, or wrestle with obscure build systems.