I’ve included my go-to design systems. I’ve chosen these because they serve some of the most widely used digital products, are maintained by mature teams with serious budgets, and have great documentation.

Name Noteworthy
Google’s Material Design See their rules on motion, dark theme and elevation
Microsoft’s Fluent See their downloadable design toolkits
Apple’s Human Interface Guidelines See their rules for keyboard shortcuts
IBM’s Carbon See their rules for colors in data visualization
Shopify’s Polaris See their rules on token naming and UX writing
Gusto’s Workbench See their robust component library
Github’s Primer See their entire section on accessibility