Apache is a free and open-source cross-platform web server software.
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.
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.
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.
Open Graph is a protocol that is used to integrate any web page into the social graph.
PHP is a general-purpose scripting language used for web development.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.
Reveal CSS animation as you scroll down a page.