Atomize by Quarkly - Library for creating atomic react components
React Native Desktop - Build OS X desktop apps using React Native
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.
Arbiter IDE - The offline-friendly, in-browser IDE for pure JS prototypes
Bootstrap - Simple and flexible HTML, CSS, and JS for popular UI components and interactions
React Native - A framework for building native apps with React