UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
Design Systems Repo - A collection of design system examples and resources
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Eva Design System - A free customizable design system
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project
Vue Design System - An open source tool for building Design Systems with Vue.js