Cloudflare Content Delivery Network (CDN) is a geographically distributed group of servers that ensure fast delivery of Internet content, including HTML pages, JavaScript files, stylesheets, and images.
Bootstrap is a free and open-source front-end framework for designing websites and web applications. It contains HTML and CSS-based design templates for typography, forms, buttons, navigation and other interface components, as well as optional JavaScript extensions.
Modernizr is a JavaScript library which is designed to detect HTML5 and CSS3 features in various browsers, which lets JavaScript avoid using unimplemented features or use a workaround such as a shim to emulate them. Modernizr aims to provide this feature detection in a complete and standardized manner.