Acquia Personalization (formerly Acquia Lift) lets you track customers' behavior throughout your website.
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.
Snowplow is an open-source behavioral data management platform for businesses.