Internet Information Services (IIS) is an extensible web server software created by Microsoft for use with the Windows NT family.
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.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.
XenForo is a PHP-based forum hosting program for communities that is designed to be deployed on a remote web server.