A Fibonacci sequence generator written in JavaScript (Node.JS).

fibonacci.js

function fibonacci (upto) {
	if(upto.length == 0) {
		console.log("Usage: fibonacci <upto>.");
	} else {
		var first = 0, second = 1, sum;
		var fibonacci_string = "";
		fibonacci_string += (first + " " + second);
		for (var counter = 0; counter < (upto - 2); counter++) {
			sum = first + second;
			fibonacci_string += (" " + sum);
			first = second;
			second = sum;
		};
		console.log(fibonacci_string);
	}
}

fibonacci(process.argv.splice(2));

Go for the latest revision.
https://gist.github.com/mayureshkathe/8486955/7cd86d9c1fc8c68db12223b7a9299c35dbcdee5a