The Monaco Editor is the code editor that powers VS Code.
Rich IntelliSense and Validation for TypeScript, JavaScript, CSS, LESS.
Basic Syntax Colorization for HTML, XML, PHP, C#, C++, Razor, Markdown, Diff, Java, VB, CoffeeScript, Handlebars, Batch, Jade, F#, Lua, Powershell, Python, SASS, R, Objective-C.

Rainbow is a code syntax highlighting library written in Javascript.
It was designed to be lightweight (1.4kb), easy to use, and extendable.
It is completely themable via CSS.

Provides functionality to perform syntax highlighting for different file formats.