Bun is a fast JavaScript runtime, bundler, transpiler, and package manager -- all in one. Key features: - Up to 4x faster startup time than Node.js - Native TypeScript and JSX support (no separate transpilation step) - Built-in package manager (npm-compatible) with global caching - Built-in test runner, bundler, and transpiler - Web-standard APIs: fetch, WebSocket, ReadableStream, etc. - Node.js compatibility: most Node.js built-in modules work out of the box - Zig, C++, and Rust -- for maximum performance
