CSTK is the "Classic Stylesheets Toolkit". It's intended as both a simple and (hopefully) performant JSX-based frontend TypeScript library based on reactive programming, and a set of widgets, layouts and utilities for building traditional desktop GUIs for the web.
The reactive parts of CSTK have been renamed and moved to Cytoplasmic. The goal of this project is still to make a set of reactive widgets based on Classic Stylesheets for building traditional desktop GUIs for the web.