GitHubDesign Systems & Foundations · Accessibility
Command-line tool that checks colour contrast across a palette or config file, suitable for CI pipelines.
Why it’s a gem
Contrast checking as a build step, not a manual browser-extension ritual.
W3C's reference implementations for thirty accessible widget patterns, each with keyboard maps, ARIA semantics and working examples.
Heydon Pickering's long-form teardowns of eleven UI patterns, each reasoning from markup semantics to progressive enhancement.
Browser extension that renders a document's heading outline and flags skipped or misordered heading levels instantly.
Automation library that drives real VoiceOver and NVDA screen readers from Playwright or Jest for end-to-end a11y tests.
T-Mobile's generator that produces accessibility acceptance criteria per component for web, iOS and Android test plans.
Accessibility suite with Figma, Sketch and browser plugins covering contrast, focus order, alt text and vision simulation.