Apache is a free and open-source cross-platform web server software.
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.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Pinterest is an image sharing and social media service designed to enable saving and discovery of information.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.