I've published an open-source rich text editor package library Taze Editor.  It provides a set of functions to help you build a rich text editor.

Docs: https://taze-editor.vercel.app
Source code: https://github.com/taze-editor/taze-editor

I've published an open-source library called Desygna. It is a simple and typesafe css-in-js solution that makes easier to create variant based components.

Docs: https://desygna.vercel.app
Source code: https://github.com/desygna/desygna