Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.
Envoy is an open-source edge and service proxy, designed for cloud-native applications.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Next.js is a React framework for developing single page Javascript applications.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Varnish is a reverse caching proxy.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.