Useful Sections for a Design System Reference Site
Material Design
Build beautiful, usable products faster. Material Design is an adaptable system—backed by open-source code—that helps teams build high quality digital experiences.
Fluent Design System
Fluent brings the fundamentals of principled design, innovation in technology, and customer needs together as one. It’s a collective approach to creating simplicity and coherence through a shared, open design system across platforms.
7 requirements of a holistic Design System
→ https://blog.marvelapp.com/holistic-design-system/
sipgate Design System
Style Guide | Frontify
Clarity 2.0 is now available
Clarity Design System
UX guidelines, HTML/CSS framework, and Angular components working together to craft exceptional experiences
SharePoint Add-ins UX design guidelines
Design | Android Developers
iOS Human Interface Guidelines
Icon and Image Sizes (iOS Human Interface Guidelines)
Learn about designing apps for iOS.
IBM Design Language
Not Your Parent's Mobile Phone: UX Design Guidelines For Smartphones