Functional Programming in JavaScript

http://dailyjs.com/2012/09/14/functional-programming/
http://eloquentjavascript.net/chapter6.html
http://stackoverflow.com/questions/3962604/is-javascript-a-functional-programming-language
http://www.srirangan.net/2011-12-functional-programming-in-javascript
http://www.ibm.com/developerworks/web/library/wa-javascript/index.html

What exactly does it mean for JavaScript to be functional? “Functional” merely describes a collection of traits a given language may or may not have. A language like Haskell has all of them: immutable variables, pattern matching, first class functions, and others. Some languages hardly have any, like C. While JavaScript certainly doesn’t have immutable variables or pattern matching it does have a strong emphasis on first class functions; mutating, combining, and using these function objects for cleaner and more succinct code is the purpose of this tutorial.