React is a JavaScript library for building user interfaces, created at Facebook. Its component-based architecture and virtual DOM transformed how web applications are built and influenced virtually every UI framework that followed.
Origins
Jordan Walke created React at Facebook in 2011 to solve challenges with Facebook’s complex, ever-changing UI. It was open-sourced in 2013 and quickly gained adoption.
Key Innovations
React introduced concepts that became standard:
- Virtual DOM: Efficient UI updates through reconciliation
- Component-based architecture: Reusable, composable UI pieces
- Declarative UI: Describe what should render, not how
- JSX: HTML-like syntax in JavaScript
- One-way data flow: Predictable state management
Evolution
React has evolved significantly:
- Hooks (2019): Simpler state and effects without classes
- Concurrent Mode: Better handling of updates
- Server Components (2023): React on the server
- Suspense: Declarative loading states
Impact
React’s influence is pervasive:
- Most popular UI library by adoption
- React Native brought it to mobile
- Inspired Vue, Svelte, and others
- Established component-based development as the standard
- Created enormous ecosystem of tools and libraries