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.
cdnjs is a free distributed JS library delivery service.
Next.js is a React framework for developing single page Javascript applications.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
React is an open-source JavaScript library for building user interfaces or UI components.
Unpkg is a content delivery network for everything on npm.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.