cdnjs is a free distributed JS library delivery service.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Java is a class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
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.
Unpkg is a content delivery network for everything on npm.