Yarn: A new package manager for JavaScript

At Facebook we're already using Yarn in production, and it's been working really well for us. It powers the dependency and package management for many of our JavaScript projects. With each migration we've enabled engineers to build offline and helped speed up their workflow.

— Sebastian McKenzie, code.facebook.com

Yarn Javascript

Yarn is a new package manager that replaces the existing workflow for the npm client or other package managers while remaining compatible with the npm registry. It has the same feature set as existing workflows while operating faster, more securely, and more reliably.

— Sebastian McKenzie, code.facebook.com

Yarn Javascript

Initially, following the prescribed best practices, we only checked in package.json and asked engineers to manually run npm install. This worked well enough for engineers, but broke down in our continuous integration environments, which need to be sandboxed and cut off from the internet for security…

— Sebastian McKenzie, code.facebook.com

Yarn Javascript

By breaking these steps down cleanly and having deterministic results, Yarn is able to parallelize operations, which maximizes resource utilization and makes the install process faster. On some Facebook projects, Yarn reduced the install process by an order of magnitude, from several minutes to just…

— Sebastian McKenzie, code.facebook.com

Javascript Package Management Facebook Open Source Yarn

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