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.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
KaTeX is a cross-browser JavaScript library that displays mathematical notation in web browsers.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Quicklink is a JS library which aims to be a drop-in solution for sites to prefetch links based on what is in the user's viewport.