Drupal is a free and open-source web content management framework.
Modernizr is a JavaScript library that detects the features available in a user's browser.
PHP is a general-purpose scripting language used for web development.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.