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.
Cloudflare Browser Insights is a tool that measures the performance of websites from the perspective of users.
Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Optimizely is an experimentation platform that helps developers build and run A/B tests on websites.
RequireJS is a JavaScript library and file loader which manages the dependencies between JavaScript files and in modular programming.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.