Apache is a free and open-source cross-platform web server software.
Drupal is a free and open-source web content management framework.
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.
Ubuntu is a free and open-source operating system on Linux for the enterprise server, desktop, cloud, and IoT.
Varnish is a reverse caching proxy.