Stack
React
4.5 / 5
The library that popularized thinking of the interface as components: pieces that receive data and return UI. The foundation of this site and of the design system that feeds it.
React fits naturally with how a product designer thinks: components with properties and states, exactly like in Figma. That one-to-one correspondence between the design system as designed and as coded is what keeps system and code from diverging.
Its ecosystem is the largest in front-end, and with Server Components the line between server and client has grown thinner and more efficient, though also harder to reason about. It's neither the lightest nor the simplest library, but it's where the community, the tooling and the talent are.