Apache is a free and open-source cross-platform web server software.
Google Analytics is a free web analytics service that tracks and reports website traffic.
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.
ShareThis provides free engagement and growth tools (e.g., share buttons, follow buttons, and reaction buttons) for site owners.