Compass
Stylesheet authoring framework
...It offers abstractions for vendor prefixes, cross-browser compatibility fixes, and reusable UI patterns like grids, buttons, and typography helpers. With Compass, developers can write cleaner Sass code that compiles into consistent CSS across browsers without hand-coding workarounds. The framework also includes a command-line tool for compiling Sass, managing sprite sheets, and integrating with build workflows. It was widely adopted in the era before modern CSS standards caught up with mixins and variables, helping developers speed up styling while reducing redundancy. While less dominant today, Compass remains an important historical tool that influenced the evolution of Sass and frontend best practices.