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.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
TYPO3 is a free and open-source Web content management system written in PHP.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.