Bun
All-in-one JavaScript runtimeOpen source· verified Oct 2026
A JavaScript runtime with an integrated package manager, bundler, and test runner. It transpiles TypeScript and JSX while executing them, and implements many Node APIs so existing packages can work with it.
Official site
Reach for it when
- Integrated installs, scripts, and tests with dependencies you have validated
- Applications whose runtime, native add-ons, and host support have been checked on Bun
Worth knowing
Execution does not type-check. Node API compatibility is incomplete; test native add-ons and deployment behavior. Using Bun as a package manager does not require using it as the production runtime.