Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Drupal is a free and open-source web content management framework.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Varnish is a reverse caching proxy.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.