Drupal is a free and open-source web content management framework.
Mautic is a free and open-source marketing automation tool for Content Management, Social Media, Email Marketing, and can be used for the integration of social networks, campaign management, forms, questionnaires, reports, etc.
PHP is a general-purpose scripting language used for web development.
ShareThis provides free engagement and growth tools (e.g., share buttons, follow buttons, and reaction buttons) for site owners.