Apache is a free and open-source cross-platform web server software.
Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
PHP is a general-purpose scripting language used for web development.
Priority Hints exposes a mechanism for developers to signal a relative priority for browsers to consider when fetching resources.
RequireJS is a JavaScript library and file loader which manages the dependencies between JavaScript files and in modular programming.