Splitting up large codebases into separate independently versioned packages is extremely useful for code sharing. However, making changes across many repositories is messy and difficult to track, and testing across repositories gets complicated really fast.
To solve these (and many other) problems, some projects will organize their codebases into multi-package repostories (sometimes called monorepos). Projects like Babel, React, Angular, Ember, Meteor, Jest, and many others develop all of their packages within a single repository. Lerna is a tool that optimizes the workflow around managing multi-package repositories with git and npm.
License: MIT License