Varnish is a reverse caching proxy.

Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.

Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.

PHP is a general-purpose scripting language used for web development.

Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update measurement codes and related code fragments collectively known as tags on your website or mobile app.

jQuery CDN is a way to include jQuery in your website without actually downloading and keeping it your website's folder.

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.

Google Analytics is a free web analytics service that tracks and reports website traffic.

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.