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.
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.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.
A modest JavaScript framework for the HTML you already have.
Unpkg is a content delivery network for everything on npm.