`node-localstorage` provides a drop‑in implementation of the browser localStorage API for Node.js. It stores key/value pairs on disk (with a configurable quota), supports the full Web Storage interface (including events, dot‑property/associative‑array syntax, and a `_sync()` method for multi‑process access), and can be used as a global polyfill in server‑side or test environments. It’s aimed at developers who need the familiar `localStorage` API when running JavaScript outside the browser.