Apache is a free and open-source cross-platform web server software.
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.
PHP is a general-purpose scripting language used for web development.
Varnish is a reverse caching proxy.
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.
WP-Optimize is an all-in-one WordPress plugin that cleans your database, compresses your large images and caches your site.
Yoast SEO is a search engine optimisation plugin for WordPress and other platforms.