Glimmer - Fast and light-weight UI components for the web
Pinegrow - A professional visual editor for Bootstrap 4 and 3, Foundation, responsive design, HTML, and CSS. Convert HTML to WordPress themes.
Preact.js - Preact is a fast 3kB alternative to React with the same modern API. Components & Virtual DOM.
BlueGriffon - An HTML editor based on Mozilla rendering engine.
Svelte - Cybernetically enhanced web apps
Webflow - Build dynamic, responsive websites in your browser. Launch with a click. Or export your squeaky-clean code to host wherever you'd like. Discover the professional website builder made for designers.