The systems worth studying when researching presets, missing axes, or component comparisons. Link-verified July 2026.
- Spectrum 2 (Adobe)
- Astryx (Meta)
- Material 3
- Geist (Vercel)
- Primer (GitHub)
- Supabase
- Atlassian
- Cloudscape (AWS)
- Carbon (IBM)
- HeroUI pro
- Beautiful UI (Turbo) — AI-native UI primitives
- interior.dev — copy-paste headless interaction primitives (layout-shift-free state changes, interruptible animations, reduced-motion)
- Shadow (Florian Kiem) — Tailwind CSS plugin for smoother, layered shadow effects