cdnjs is a free distributed JS library delivery service.
Drupal is a free and open-source web content management framework.
Google Analytics is a free web analytics service that tracks and reports website traffic.
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.
Matter.js is a 2D physics engine for the web. It provides JavaScript-based tools for simulating rigid body physics in 2D environments.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Polyfill is a service which accepts a request for a set of browser features and returns only the polyfills that are needed by the requesting browser.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.