Apache is a free and open-source cross-platform web server software.
W3 Total Cache (W3TC) improves the SEO and increases website performance and reducing load times by leveraging features like content delivery network (CDN) integration and the latest best practices.
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-PageNavi is a WordPress plugin which adds a more advanced paging navigation interface to your WordPress blog.