Metro

Judgement

What it is

Developer tool

What it does

The JavaScript bundler and development server that React Native uses to build and reload app code.

Adopt it when

You build a React Native app, where it comes included and is the default.

Watch out

It is shaped for React Native and is rarely a good fit for web bundling.

Ready for

Production-ready

Runs as

Command line and library

Built with

JavaScript and Node.js

How established

Established: started 10 years ago, latest release v0.87.3.

What the license allows

You can build it into a product you sell, as long as you keep its copyright notice.

Judged on 2026-11-06 from the project's README and GitHub data. The license and age lines are worked out directly.

Built from

Follow it down: Metro → V8 → LLVM project → runs on a microchip

How compilers were built, back to punched paper tape

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