Astryx: Meta’s Open‑Source Design System Powers 13k Apps with 150+ Accessible Components
Astryx delivers a fully composable, themable UI library used in over 13,000 Meta applications. With more than 150 accessible components, it avoids styling lock‑in by exposing raw CSS and supports any framework via plain className overrides. The open internals let developers swizzle source code for deep customization without forks.