Apache is a free and open-source cross-platform web server software.
Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
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.
Typekit is an online service which offers a subscription library of fonts.
Varnish is a reverse caching proxy.