Apache is a free and open-source cross-platform web server software.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
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.