Apache is a free and open-source cross-platform web server software.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Popper is a positioning engine, its purpose is to calculate the position of an element to make it possible to position it near a given reference element.
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.
Tippy.js is the complete tooltip, popover, dropdown, and menu solution for the web, powered by Popper.
Unpkg is a content delivery network for everything on npm.