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.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
Ruby on Rails is a server-side web application framework written in Ruby under the MIT License.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.