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.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
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.
LiteSpeed is a high-scalability web server.
Popper is a positioning engine, its purpose is to calculate the position of an element to make it possible to position it near a given reference element.
Typekit is an online service which offers a subscription library of fonts.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.