Bun
ELI5 — The Vibe Check
Bun is a JavaScript runtime (like Node.js) that does everything faster — starting up, installing packages, running tests, bundling code. It's an all-in-one toolkit: runtime + package manager + bundler + test runner. Instead of node + npm + webpack + jest, you just use bun. It's written in Zig for maximum speed. Install 500 packages? 2 seconds. Run your tests? Near-instant. It's the impatient developer's dream.
Real Talk
Bun is a high-performance JavaScript/TypeScript runtime built on JavaScriptCore (Safari's engine) instead of V8 (Chrome's engine). Written in Zig, it provides significantly faster startup, I/O operations, and package installation compared to Node.js. It includes a native bundler, test runner, and npm-compatible package manager. Bun aims for Node.js API compatibility while offering native TypeScript/JSX support, built-in SQLite, and a fast HTTP server.
When You'll Hear This
"We switched the dev server to Bun and startup went from 3 seconds to 200ms." / "bun install is so fast it feels broken — 500 packages in under 2 seconds."
Related Terms
Deno
Deno is a JavaScript runtime created by the same person who made Node.js — as a 'do-over' to fix Node's mistakes.
Node.js
Node.js lets you run JavaScript on the server — not just in the browser. Before Node.js, JavaScript was trapped in the browser.
npm
npm is like a vending machine for code. You say 'I want React' and it delivers React, plus React's 47 friends, plus their friends' friends.
Package Manager
A package manager is the app store for your code — it downloads libraries, manages versions, and makes sure everything plays nice together. It's like a gro