cdnjs is a free distributed JS library delivery service.
Emotion is a library designed for writing CSS styles with JavaScript.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
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.
Open Graph is a protocol that is used to integrate any web page into the social graph.
React is an open-source JavaScript library for building user interfaces or UI components.
Sentry is an open-source platform for workflow productivity, aggregating errors from across the stack in real time.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.