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.
Internet Information Services (IIS) is an extensible web server software created by Microsoft for use with the Windows NT family.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
Typekit is an online service which offers a subscription library of fonts.