Bun

Bun is an all-in-one JavaScript toolkit, including a runtime, package manager, test runner, and bundler.

Runtime: Bun is a JavaScript runtime built on top of JavaScriptCore, the engine that powers WebKit. It’s designed to be a drop-in replacement for Node.js, while being faster and improving developer experience. It also includes built-in support for TypeScript and JSX.

Package manager: Bun includes a package manager that’s vastly quicker than npm and Yarn, and is compatible with existing Node.js projects.

Test runner: Bun includes a Jest-compatible test runner that uses the Bun runtime. It supports TypeScript and JSX, lifecycle hooks, and UI/DOM testing.