Google Analytics is a free web analytics service that tracks and reports website traffic.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Instant.Page is a JavaScript library which uses just-in-time preloading technique to make websites faster.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Netlify providers hosting and server-less backend services for web applications and static websites.
Unpkg is a content delivery network for everything on npm.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.