This extension is based on a script by Lea Verou: https://www.prismjs.com

Prism is a lightweight, extensible syntax highlighter, built with modern web standards in mind. This extension makes is easy to add syntax highlighting to your website. It has support for the following languages: applescript ,c, coffeescript, cpp, cs, csharp, css, html, java, javascript, perl, php, python, ruby, sass, scss, sql, svg, swift, xml.

prism.js