Google Analytics is a free web analytics service that tracks and reports website traffic.
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.
Microsoft Ajax Content Delivery Network hosts popular third party JavaScript libraries such as jQuery and enables you to easily add them to your web applications.
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.
Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.