cdnjs is a free distributed JS library delivery service.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
Google PageSpeed is a family of tools designed to help websites performance optimisations.
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.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Unpkg is a content delivery network for everything on npm.
Vue.js is an open-source model–view–viewmodel JavaScript framework for building user interfaces and single-page applications.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.