Frameworks and Libraries

Packaged inside Foundry VTT are a number of JavaScript libraries and frameworks which can be leveraged in module and system-development without having to be separately included.


Handlebars is a simple templating language used by Foundry VTT to structure HTML based on JS object data stored by systems, modules, and FVTT itself. You can find out more about Handlebars by clicking here.


jQuery is a fast, small, and feature-rich JavaScript library. Foundry VTT comes packaged with jQuery included and uses it to assist primarily in reading and manipulating HTML documents.

You can find out more about jQuery here.


PixiJS is a powerful HTML5 WebGL library which powers FoundryVTT's canvas, it is extremely robust and provides FVTT with its lighting renderer and many other Scene features. Numerous modules leverage PixiJS to extend Foundry VTT in profound ways, adding lighting, filters, and even animated effects.

You can find out more about PixiJS here.


GreenSock is a javascript library designed for animating SVG, WebGL, and HTML objects in conjunction with Pixi. Foundry exposes GreenSock in its API, allowing module and system developers to leverage the platform inside FVTT.

You can find out more about Greensock here.