• .pulse – by Heartbeat
• Ant Design
• Apple Design Resources
• Atlaskit – by Atlassian
• Audi
• Bolt Design System
• Carbon Design System – by IBM
• Clarity Design System – by VMware
• Comet – by Discovery Education
• Design Systems – by Figma – publication about design systems
• E*TRADE Design – by E*TRADE
• Evergreen – by Segment
• Fundamental Library – by SAP
• GOV.UK Design System – by the U.K. government
• Infor Design – by Infor
• Lexicon – by Liferay
• Lightning Design System – by Salesforce
• Mailchimp Patterns
• Marvel Styleguide – by Marvel
• Material Design – by Google
• Microsoft Fluent UI
• Mozilla Protocol – for Mozilla and Firefox websites
• Oracle Alta UI
• PatternFly – by Red Hat
• Photon Design System – by Mozilla
• Pluralsight Design System
• Primer – by GitHub
• Rizzo – by Lonely Planet
• SendGrid Style Guide
• The Guardian digital design style guide
• U.S. Web Design System – by the U.S.A government
• University of Oxford: Digital style guide
• VTEX Styleguide – by VTEX
• Wikimedia Design Style Guide
• Workday Canvas Design System – by Workday
• Yelp Styleguide

Also see: github.com/bradtraversy/design-resources-for-developers