Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.
cdnjs is a free distributed JS library delivery service.
Font Awesome is a font and icon toolkit based on CSS and Less.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Lodash is a JavaScript library which provides utility functions for common programming tasks using the functional programming paradigm.