Acquia Cloud Platform is a Drupal-tuned application lifecycle management suite with an infrastructure to support Drupal deployment workflow processes.
Acquia Site Factory is a multisite platform for Drupal.
Drupal Multisite enables separate, independent sites to be served from a single codebase.
Drupal is a free and open-source web content management framework.
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.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Varnish is a reverse caching proxy.