Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
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.
OWL Carousel is an enabled jQuery plugin that lets you create responsive carousel sliders.
PHP is a general-purpose scripting language used for web development.
Varnish is a reverse caching proxy.