Google Analytics is a free web analytics service that tracks and reports website traffic.
Gravatar is a service for providing globally unique avatars.
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.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.