SpiderMonkey JavaScript library

 SpiderMonkey is the code-name for Mozilla Firefox's C++ implementation of
 JavaScript. It is intended to be embedded in other applications
 that provide host environments for JavaScript.
 .
 This library is intended for use in contexts where only trusted
 JavaScript code will be run, such as GNOME's gjs, Cinnamon's cjs, and
 polkit's rules parsing. It should not be used to run untrusted JavaScript
 from web pages: use a security-supported implementation such as Firefox,
 Chrome or WebKitGTK's JavaScriptCore instead.