This document compares the Bootstrap and Foundation front-end frameworks. Both frameworks provide pre-built CSS and JavaScript components to help build responsive websites, but they differ in some key ways. Bootstrap uses Less/Sass and supports IE8 with polyfills, while Foundation only uses Sass and does not support IE8. Foundation has a more flexible grid system and "mobile-first" CSS, while Bootstrap requires adding classes for full responsiveness. Overall, the document analyzes the differences in functionality, compatibility, and implementation of these popular front-end frameworks.