bootstrap‑sass‑loader is a (now deprecated) Webpack loader that simplifies importing and customizing the Sass version of Twitter Bootstrap in a Webpack‑based build. It lets developers pull in Bootstrap’s styles and scripts, optionally overriding variables via a configuration file, and is aimed at front‑end developers using Webpack (especially those working with Rails‑React stacks) who want an easy way to integrate Bootstrap‑Sass into their projects.