cdnjs is a free distributed JS library delivery service.
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.
Zurb Foundation is used to prototype in the browser. Allows rapid creation of websites or applications while leveraging mobile and responsive technology. The front end framework is the collection of HTML, CSS, and Javascript containing design patterns.