Figma Simple Design System vs GitHub Primer

Figma Simple Design System has no write-up on Specifiction yet; its figures are above.

GitHub Primer is a free, open-source design system for designing and building GitHub interfaces. Its guidance covers product UI components, patterns, and design tokens for color, spacing, and typography. Primer Brand addresses marketing websites and other digital experiences. React documentation explains theming, recommended practices, and component extension. Primer also provides accessibility guidance and tools, along with Octicons, GitHub’s scalable icon set. Product UI documentation includes an MCP server page. Component status is identified as experimental, ready, or deprecated; ready components are described as mature with long-term support expected. Primer Web and Primer Primitives are available through the Primer Figma Community page, while GitHub’s Figma organization is limited to GitHub team members. The Primer Mobile Figma library is internal only. GitHub employees alone can contribute to Primer Web because of Figma’s open-source file handling. GitHub’s Design Infrastructure and Design Engineering teams maintain the CSS framework, documentation, tools, libraries, and component libraries.