Apache is a free and open-source cross-platform web server software.
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.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
SWFObject is an open-source JavaScript library used to embed Adobe Flash content onto web pages.