Select2 - Select2 offers customizable select box with support for searching, tagging, infinite scrolling, and many other used options.
wxWidgets - wxWidgets: Cross-Platform GUI Library
Materialize CSS - A modern responsive front-end framework based on Material Design
Electron - Build cross platform desktop apps with web technologies
Bulma - Bulma is an open source CSS framework based on Flexbox and built with Sass. It's 100% responsive, fully modular, and available for free.
GTK - GTK+ is a multi-platform toolkit for creating graphical user interfaces.