`include‑all` is a Node.js utility that recursively reads a directory and builds an object containing all matching modules, with support for filtering, optional loading (silently returning an empty object if the folder is missing), and several asynchronous helpers (`optional`, `exists`, `aggregate`). It’s primarily used by Sails.js (and similar frameworks) to auto‑load controllers, models, configs, etc., making it useful for developers who want a simple, configurable way to require whole folders of modules.