Apache is a free and open-source cross-platform web server software.
jQuery UI is a collection of GUI widgets, animated visual effects, and themes implemented with jQuery, Cascading Style Sheets, and HTML.
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.
ProcessWire is an open source content management system (CMS) and framework (CMF).
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.