Apache is a free and open-source cross-platform web server software.
Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.
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.
MODX (originally MODx) is an open source content management system and web application framework for publishing content on the World Wide Web and intranets.
PHP is a general-purpose scripting language used for web development.