Quick and dirty "blind" implementation of the functionality found at https://github.com/trevorparscal/more-underscore

more-underscore.js

var _ = {
	objectify: function (arr) {
		var o = {},
			vals = arguments['0'];
		for (var i = 1; i < arguments.length; ++i) {
			if (i > vals.length) break;
			o[arguments[i.toString()]] = vals[i - 1];
		}
		return o;
	},
	traverse: function (value, path, steps) {
		if (!value || value.length === 0) return null;

		value = value[path[0]];
		if (path.length === 1) {
			return value;
		} else {
			return this.traverse(value, path.slice(1, path.length), steps);
		}
	},
	inject: function (arr, offset, items) {
		// concats items to parameter list to get around
		// array flattening problems
		// WARNING: this could go past the js arguments length limit
		// but i don't care for this sample code
		// NOTE: i had to look up the answer to this one
		// to find a better way to do it in-place
		arr.splice.apply(arr, [offset, 0].concat(items));
	},
	extendClass: function (dst, src) {
		dst.prototype = Object.create(src.prototype);
	}
}

function testExtend() {
	// Define parent class
	function Foo() {}
	Foo.prototype.x = function () {}
	Foo.prototype.y = function () {}
	// Define child class
	function Bar() {
		Foo.call(this);
	}
	Foo.prototype.y = "y";
	// Extend prototype
	_.extendClass(Bar, Foo);

	if (Bar.prototype.x === undefined) {
		console.log("Extend failed: property 'x' not included");
	}

	if (Bar.prototype.y !== "y") {
		console.log("Extend failed: property 'x' not included");
	}
}

function testObjectify() {
	var res = _.objectify([1, 2], 'a', 'b'),
		exp = {
			'a': 1,
			'b': 2
		};
	if (JSON.stringify(res) !== JSON.stringify(exp)) {
		console.log("Objectify failed:", res, "not equal", exp)
	}
}

function testTraverse() {
	var res = _.traverse({
			'a': ['b', 'c', {
				'd': 'test'
			}]
		}, ['a', 2, 'd']),
		exp = 'test';
	if (JSON.stringify(res) !== JSON.stringify(exp)) {
		console.log("Traverse failed:", res, "not equal", exp)
	}
}

function testInject() {
	var arr = [0, 1, 2, 3],
		exp = [0, 1, 'a', 'b', 'c', 2, 3];
	_.inject(arr, 2, ['a', 'b', 'c']);
	if (JSON.stringify(arr) !== JSON.stringify(exp)) {
		console.log("Traverse failed:", arr, "not equal", exp);
	}
}

testObjectify();
testTraverse();
testInject();
testExtend();