Source Wireframe Kit - Library of 537 blocks for desktop and mobile prototyping
React Native Desktop - Build OS X desktop apps using React Native
Contra Wireframe Kit - Open source wireframe kit for design and prototyping 🚀
Arbiter IDE - The offline-friendly, in-browser IDE for pure JS prototypes
Platforma - Wireframe library of layouts and UI elements
CodeOnline - A remote and secure workspace powered by VSCode