HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Leaflet is the open-source JavaScript library for mobile-friendly interactive maps.
Materialize CSS is a front-end framework that helps developers create responsive and mobile-first web applications. It is based on Google's Material Design guidelines.
Netlify providers hosting and server-less backend services for web applications and static websites.
Open Graph is a protocol that is used to integrate any web page into the social graph.