Acquia Cloud Platform is a Drupal-tuned application lifecycle management suite with an infrastructure to support Drupal deployment workflow processes.
Drupal is a free and open-source web content management framework.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Open Graph is a protocol that is used to integrate any web page into the social graph.
ShareThis provides free engagement and growth tools (e.g., share buttons, follow buttons, and reaction buttons) for site owners.
Varnish is a reverse caching proxy.