Google Analytics is a free web analytics service that tracks and reports website traffic.
Headroom.js is a JS widget that allows you to react to the user's scroll. The header slides out of view when scrolling down and slides back in when scrolling up.
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.
RequireJS is a JavaScript library and file loader which manages the dependencies between JavaScript files and in modular programming.