cdnjs is a free distributed JS library delivery service.
Drupal is a free and open-source web content management framework.
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.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.