Integrating vanilla JavaScript UI libraries into Svelte

First, we will explore UI libraries that are written in vanilla JavaScript. When we use the phrase vanilla JavaScript, we’re referring to plain JavaScript, or JavaScript in the absence of frameworks or libraries.

There are many reasons a UI library is written in vanilla JavaScript:

• Performance reasons – it would be much easier to optimize without the abstractions from the web framework
• The library author’s personal preference to be framework-agnostic
• The library was created predating any modern web frameworks

For us, vanilla JavaScript UI libraries are great because they do not depend on any specific framework runtime, which is an extra overhead on top of the UI library itself.

For example, if we use a calendar component library that is implemented in React, then besides installing the calendar component library, we would need to install React’s framework as well.

This...