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.

WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.

Yoast SEO is a search engine optimisation plugin for WordPress and other platforms.

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.

Elementor is a website builder platform for professionals on WordPress.

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

Contact Form 7 is an WordPress plugin which can manage multiple contact forms. The form supports Ajax-powered submitting, CAPTCHA, Akismet spam filtering.

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

Query Migrate is a javascript library that allows you to preserve the compatibility of your jQuery code developed for versions of jQuery older than 1.9.

MySQL is an open-source relational database management system.

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

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

Underscore.js is a JavaScript library which provides utility functions for common programming tasks. It is comparable to features provided by Prototype.js and the Ruby language, but opts for a functional programming design instead of extending object prototypes.