cdnjs is a free distributed JS library delivery service.
Font Awesome is a font and icon toolkit based on CSS and Less.
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.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
Select2 is a jQuery based replacement for select boxes. It supports searching, remote data sets, and infinite scrolling of results.
Unpkg is a content delivery network for everything on npm.