<model-viewer> is an open-source web component developed by Google and maintained through GitHub. <model-viewer> aims at putting 3D content on the web easily with a few lines of HTML code. This was first introduced with Chrome 72 in July 2019 and enables users to view 3D in the browser and mobile devices.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.