Apache is a free and open-source cross-platform web server software.
Contao is an open source CMS that allows you to create websites and scalable web applications.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
PHP is a general-purpose scripting language used for web development.
Stellar.js is a JavaScript library and jQuery plugin specifically designed to deliver parallax scrolling effects for web pages.