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.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Moment.js is a free and open-source JavaScript library that removes the need to use the native JavaScript Date object directly.
Vercel is a cloud platform for static frontends and serverless functions.