Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
cdnjs is a free distributed JS library delivery service.
Drupal Multisite enables separate, independent sites to be served from a single codebase.
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.
MathJax is a cross-browser JavaScript library that displays mathematical notation in web browsers, using MathML, LaTeX and ASCIIMathML markup.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.