Apache is a free and open-source cross-platform web server software.
Drupal is a free and open-source web content management framework.
Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
Gravatar is a service for providing globally unique avatars.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Open Graph is a protocol that is used to integrate any web page into the social graph.