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 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.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Personio is the all-in-one HR software for small- and medium-sized companies with 10 to 2000 employees.