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 Analytics is a free web analytics service that tracks and reports website traffic.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
ShareThis provides free engagement and growth tools (e.g., share buttons, follow buttons, and reaction buttons) for site owners.