gistfile1.js

// ==UserScript==
// @name        Due Badge
// @namespace   http://fluidapp.com
// @description Displays a dock badge for items in a certain Remember The Milk list.
// @include     *
// @author      Edd Morgan <trquadrant.com>
// ==/UserScript==

(function () {
	if (window.fluid) {
		// URL to your target list (could be a smart list) on RTM
		var due_list_atom_url = "http://www.rememberthemilk.com/atom/eddm/0123456/"
		var timeout = 30; // Time, in seconds, between updates

		function makeReq(url, callback) {
			var request = new XMLHttpRequest();
			request.open("POST", url, true);
			request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); 
			request.onreadystatechange = function() {
				if (request.readyState == 4 && request.status == 200) {
					if (request.responseText) {
						handleResponse(request.responseText, callback);
					}
				}
			}
			request.send(null);
		}

		function handleResponse(response, callback) {
			var parser = new DOMParser();
			var doc = parser.parseFromString(response,"text/xml");
			callback(doc.documentElement);
		}

		function parse(data) {
			var items = data.getElementsByTagName('entry');
			if(items.length > 0) {
				window.fluid.dockBadge = "" + items.length + "";
			} else {
				window.fluid.dockBadge = null;
			}
		}

		function loadfeed(url) {
			makeReq(url, parse);
			setTimeout(initRequest, timeout * 1000);
		}

		function initRequest() {
			loadfeed(due_list_atom_url);
		}

		initRequest();
	}
	
})();