GitHub Pages is a static site hosting service.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
Gravatar is a service for providing globally unique avatars.
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.
Lodash is a JavaScript library which provides utility functions for common programming tasks using the functional programming paradigm.
Modernizr is a JavaScript library that detects the features available in a user's browser.
Open Graph is a protocol that is used to integrate any web page into the social graph.