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.
Modernizr is a JavaScript library that detects the features available in a user's browser.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.