xCSS : xCSS bases on CSS and empowers a straightforward and object-oriented workflow when developing complex style cascades.
Milligram : Milligram provides a minimal setup of styles for a fast and clean starting point. Just it! Only 2kb gzipped! It's not about a UI framework. Specially ...
InK - Interface Kit : Ink is a set of tools for quick development of web interfaces.
Foundation : An easy to use, powerful, and flexible framework for building prototypes and production code on any kind of device.
Electron : Build cross platform desktop apps with web technologies
