cdnjs is a free distributed JS library delivery service.
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.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
Open Graph is a protocol that is used to integrate any web page into the social graph.
OWL Carousel is an enabled jQuery plugin that lets you create responsive carousel sliders.
Typekit is an online service which offers a subscription library of fonts.