Verdaccio is a simple, zero-config-required local private npm registry. No need for an entire database just to get started! Verdaccio comes out of the box with its own tiny database, and the ability to proxy other registries (eg. npmjs.org), caching the downloaded modules along the way. For those looking to extend their storage capabilities, Verdaccio supports various community-made plugins to hook into services such as Amazon's s3 and Google Cloud Storage.
Use private packages
If you want to use all benefits of npm package system in your company without sending all code to the public, and use your private packages just as easy as public ones.
Cache npmjs.org registry
If you have more than one server you want to install packages on, you might want to use this to decrease latency
Link multiple registries
If you use multiples registries in your organization and need to fetch packages from multiple sources in one single project you might take advance of the uplinks feature with Verdaccio, chaining multiple registries and fetching from one single endpoint.
Override public packages
If you want to use a modified version of some 3rd-party package (for example, you found a bug, but maintainer didn't accept pull request yet), you can publish your version locally under the same name.