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.
Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.
PHP is a general-purpose scripting language used for web development.