Apache is a free and open-source cross-platform web server software.

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.

cdnjs is a free distributed JS library delivery service.

Popper is a positioning engine, its purpose is to calculate the position of an element to make it possible to position it near a given reference element.

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.

jQuery UI is a collection of GUI widgets, animated visual effects, and themes implemented with jQuery, Cascading Style Sheets, and HTML.

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

Font Awesome is a font and icon toolkit based on CSS and Less.

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.

reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.

JSDelivr is a free public CDN for open-source projects. It can serve web files directly from the npm registry and GitHub repositories without any configuration.