Apache is a free and open-source cross-platform web server software.
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.
PrestaShop is a freemium, open-source ecommerce solution, written in the PHP programming language with support for the MySQL database management system.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.