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.
Facebook pixel is an analytics tool that allows you to measure the effectiveness of your advertising.
Klarna Checkout is a complete payment solution where Klarna handles a store's entire checkout.
PayPal is an online payments system that supports online money transfers and serves as an electronic alternative to traditional paper methods like checks and money orders.
PHP is a general-purpose scripting language used for web development.
RequireJS is a JavaScript library and file loader which manages the dependencies between JavaScript files and in modular programming.