Google Analytics is a free web analytics service that tracks and reports website traffic.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Mailchimp is a marketing automation platform and email marketing service.
Open Graph is a protocol that is used to integrate any web page into the social graph.
SEOmatic facilitates modern SEO best practices & implementation for Craft CMS 3.
Typekit is an online service which offers a subscription library of fonts.