cdnjs is a free distributed JS library delivery service.
Font Awesome is a font and icon toolkit based on CSS and Less.
Leaflet is the open-source JavaScript library for mobile-friendly interactive maps.
Mapbox GL JS is a JavaScript library that uses WebGL to render interactive maps from vector tiles and Mapbox styles.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Open Graph is a protocol that is used to integrate any web page into the social graph.