A implementation of the "compose" function that takes a arbitrary number of functions.

compose.js

var compose = function () {
    //take the functions passed in as an array.
    var fns = [].slice.call(arguments, 0);
    //returns a function that will combine all of them
    return function (arg) {
         return fns.reduce(function (retValue, next) {
                return next.call(null, retValue);
         }, arg); //the initial value will be the argument
    };
};