GitHubDesign Systems & Foundations · Accessibility
Stylelint plugin that catches accessibility problems in CSS itself, such as removed outlines and unsafe media-query overrides.
Why it’s a gem
Catches a11y bugs at the CSS layer, where linters normally never look.
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.
Command-line tool that checks colour contrast across a palette or config file, suitable for CI pipelines.
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.