Design Systems
Apple HIG
Apple
Apple Human Interface Guidelines is a set of design principles, guidelines, and recommendations provided by Apple to help developers create consistent and user-friendly software apps and user interfaces for Apple's various platforms.

Material Design
Material is a design system created by Google to help teams build high-quality digital experiences for Android, iOS, Flutter, and the web.

Polaris
Shopify
Polaris is the blueprint for Shopify's design system. It helps collaborate across disciplines to build a great experience for all of Shopify's merchants.
Fluent
Microsoft
Fluent is Microsoft's design system for creating web experiences. It provides a comprehensive set of design guidelines, components, and tools to create consistent, accessible, and beautiful experiences across Microsoft's products.
Carbon
IBM
Carbon is IBM's open source design system for products and digital experiences. With the IBM Design Language as its foundation, the system consists of working code, design tools and resources, human interface guidelines, and a vibrant community of contributors.

Atlassian Design System
Atlassian
Atlassian's design system helps teams create high-quality enterprise software that's cohesive, beautiful, and easy to use. It provides a comprehensive set of guidelines, components, and tools for building consistent experiences across Atlassian's products.

Ant Design
Alibaba
An enterprise-class UI design language and React UI library with a set of high-quality React components, one of the best React UI libraries for enterprises.