The Wikimedia Codex design system is analogous to Google's Material Design, Shopify's Polaris, or IBM's Carbon
Codex is the Design System for Wikimedia. Codex features a toolkit for building user interfaces, containing design tokens, Vue 3 components and VitePress documentation site packages. The GitHub repo is a mirror from https://gerrit.wikimedia.org/g/design/codex/
See mw:Codex for details about using the system and it's relationship to prior efforts like MediaWiki UI (deprecated) or OOUI
Quick notes about the SMWCon2023 presentation are at SemanticMediaWiki
Accessibility baked in
In the README of the repo, it states: Web accessibility compliant (Web Content Accessibility Guidelines 2.1 level AA). More at Accessibility