cdnjs is a free distributed JS library delivery service.
Hoefler&Co is a digital type foundry (font design studio) in Woburn, Massachusetts (formerly New York City), founded by type designer Jonathan Hoefler. Hoefler&Co designs typefaces for clients and for retail on its website.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Svelte is a free and open-source front end compiler created by Rich Harris and maintained by the Svelte core team members.
Vercel is a cloud platform for static frontends and serverless functions.