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.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Sumo is a plugin offering set of marketing tools to automate a website's growth. These tools help drive extra traffic, engage visitors, increase email subscribers and build community.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.