Apache is a free and open-source cross-platform web server software.
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.
LazySizes unveilhooks plugin extends lazySizes to lazyload scripts/widgets, background images, styles and video/audio elements.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Javascript forms validation script.
TYPO3 is a free and open-source Web content management system written in PHP.