cdnjs is a free distributed JS library delivery service.
Google AdSense is a program run by Google through which website publishers serve advertisements that are targeted to the site content and audience.
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.
JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.