Calendly is an app for scheduling appointments, meetings, and events.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Instant.Page is a JavaScript library which uses just-in-time preloading technique to make websites faster.
Open Graph is a protocol that is used to integrate any web page into the social graph.
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.
Unpkg is a content delivery network for everything on npm.
Vercel is a cloud platform for static frontends and serverless functions.