diff --git a/drivers/firefox/data/js/panel.js b/drivers/firefox/data/js/panel.js
index 694791549..40e233d96 100644
--- a/drivers/firefox/data/js/panel.js
+++ b/drivers/firefox/data/js/panel.js
@@ -10,18 +10,18 @@
 			detectedApps.removeChild(detectedApps.firstChild);
 		}
 
-		if ( message.tabCache.count > 0 ) {
+		if ( message.tabs.count > 0 ) {
 			empty.style.display = 'none';
 
-			for ( appName in message.tabCache.appsDetected ) {
+			for ( appName in message.tabs.appsDetected ) {
 				div   = d.createElement('div');
 				a     = d.createElement('a');
 				img   = d.createElement('img');
 				label = d.createElement('span');
 				name  = d.createElement('span');
 
-				confidence = message.tabCache.appsDetected[appName].confidenceTotal;
-				version    = message.tabCache.appsDetected[appName].version;
+				confidence = message.tabs.appsDetected[appName].confidenceTotal;
+				version    = message.tabs.appsDetected[appName].version;
 
 				div.setAttribute('class', 'detected-app');
 
diff --git a/drivers/firefox/lib/driver.js b/drivers/firefox/lib/driver.js
index 9cbb17680..5fcf3b692 100644
--- a/drivers/firefox/lib/driver.js
+++ b/drivers/firefox/lib/driver.js
@@ -2,19 +2,16 @@
 	'use strict';
 
 	var
+		w = require('wappalyzer').wappalyzer,
 		{Cc, Ci} = require('chrome'),
-		main = require('wappalyzer'),
-		w = main.wappalyzer,
-		tabCache = {},
 		headersCache = {},
 		categoryNames = {},
-		initTab,
+		windows = [],
+		Window,
+		Tab,
 		Panel,
-		panel,
 		Widget,
-		widget,
-		UrlBar,
-		urlBar;
+		UrlBar;
 
 	exports.main = function(options, callbacks) {
 		w.log('main: ' + options.loadReason);
@@ -23,26 +20,144 @@
 	};
 
 	exports.onUnload = function(reason) {
+		var win;
+
 		w.log('unload: ' + reason);
 
-		if ( urlBar ) {
-			urlBar.destroy();
+		for each ( win in windows ) {
+			win.destroy();
+		}
+	};
+
+	Window = function(win) {
+		var
+			self = this,
+			tab;
+
+		this.window = win;
+		this.tabs   = {};
+		this.urlBar = null;
+		this.widget = null;
+
+		if ( require('sdk/simple-prefs').prefs.urlbar ) {
+			this.urlBar = new UrlBar();
+		} else {
+			this.widget = new Widget();
+		}
+
+		require('sdk/simple-prefs').on('urlbar', function() {
+			self.destroy();
+
+			if ( require('sdk/simple-prefs').prefs.urlbar ) {
+				self.urlBar = new UrlBar();
+			} else {
+				self.widget = new Widget();
+			}
+
+			self.displayApps();
+		});
+
+		for each ( tab in this.window.tabs ) {
+			this.tabs[tab.id] = new Tab(tab);
+		}
+
+		this.window.tabs
+			.on('open', function(tab) {
+				self.tabs[tab.id] = new Tab(tab);
+			})
+			.on('close', function(tab) {
+				self.tabs[tab.id] = null;
+			})
+			.on('activate', function(tab) {
+				self.displayApps();
+			});
+
+		self.displayApps();
+	};
+
+	Window.prototype.displayApps = function() {
+		var
+			self = this,
+			tab = this.window.tabs.activeTab,
+			url,
+			count = 0,
+			message = {};
+
+		w.log('Window.displayApps');
+
+		if ( !tab || require('sdk/tabs').activeTab !== tab ) {
+			return;
 		}
 
-		if ( widget ) {
-			widget.destroy();
+		url   = tab.url.replace(/#.*$/, '');
+		count = w.detected[url] ? Object.keys(w.detected[url]).length : 0;
+
+		this.tabs[tab.id].count = count;
+		this.tabs[tab.id].appsDetected = w.detected[url];
+
+		message = {
+			tabs: this.tabs[tab.id],
+			apps: w.apps,
+			categories: w.categories,
+			categoryNames: categoryNames
+		};
+
+		if ( this.urlBar ) {
+			this.urlBar.clear();
+
+			// Add icons
+			if ( count ) {
+				for ( appName in this.tabs[tab.id].appsDetected ) {
+					this.urlBar.addIcon(appName);
+				}
+			} else {
+				this.urlBar.addIcon();
+			}
+
+			this.urlBar.panel.get().port.emit('displayApps', message);
 		}
 
-		if ( panel ) {
-			panel.destroy();
+		if ( this.widget ) {
+			this.widget.setIcon();
+
+			if ( count ) {
+				var
+					appName,
+					found = false;
+
+				// Find the main application to display
+				w.driver.categoryOrder.forEach(function(match) {
+					for ( appName in w.detected[url] ) {
+						w.apps[appName].cats.forEach(function(cat) {
+							if ( cat == match && !found ) {
+								self.widget.setIcon(appName);
+
+								found = true;
+							}
+						});
+					}
+				});
+			}
+
+			this.widget.panel.get().port.emit('displayApps', message);
 		}
 	};
 
-	initTab = function(tab) {
-		w.log('initTab');
+	Window.prototype.destroy = function() {
+		if ( this.urlBar ) {
+			this.urlBar.destroy();
+
+			this.urlBar = null;
+		}
+
+		if ( this.widget ) {
+			this.widget.destroy();
 
-		tabCache[tab.id] = { count: 0, appsDetected: [] };
+			this.widget = null;
+		}
+	};
 
+	Tab = function(tab) {
 		tab.on('ready', function(tab) {
 			var worker = tab.attach({
 				contentScriptFile: require('sdk/self').data.url('js/tab.js')
@@ -64,11 +179,6 @@
 		});
 	};
 
-	require('sdk/tabs')
-		.on('open', initTab)
-		.on('close', function(tab) { tabCache[tab.id] = null; })
-		.on('activate', function(tab) { w.driver.displayApps(); });
-
 	Panel = function() {
 		var self = this;
 
@@ -99,27 +209,37 @@
 		this.panel.destroy();
 	};
 
-	Widget = function(panel) {
+	Widget = function() {
+		this.panel = new Panel();
+
 		this.widget = require('sdk/widget').Widget({
-			id: 'wappalyzer',
+			id: 'wappalyzer-' + ( new Date() ).getTime() + ( Math.floor( Math.random() * 900 ) + 100 ),
 			label: 'Wappalyzer',
 			contentURL: require('sdk/self').data.url('images/icon32.png'),
-			panel: panel.get()
+			panel: this.panel.get()
 		});
 	};
 
+	Widget.prototype.setIcon = function(appName) {
+		var url = typeof appName === 'undefined' ? 'images/icon32_hot.png' : 'images/icons/' + appName + '.png';
+
+		this.get().contentURL = require('sdk/self').data.url(url);
+	};
+
 	Widget.prototype.get = function() {
 		return this.widget;
 	};
 
 	Widget.prototype.destroy = function() {
+		this.panel.destroy();
+
 		this.widget.destroy();
 	};
 
-	UrlBar = function(panel) {
+	UrlBar = function() {
 		var self = this;
 
-		this.panel = panel;
+		this.panel = new Panel();
 
 		this.onClick = function() {
 			self.panel.get().show();
@@ -130,8 +250,8 @@
 
 		this.urlBar = this.document.createElement('hbox');
 
-		this.urlBar.setAttribute('id',          'wappalyzer-urlbar');
-		this.urlBar.setAttribute('style',       'cursor: pointer; margin: 0 2px;');
+		this.urlBar.setAttribute('id', 'wappalyzer-urlbar');
+		this.urlBar.setAttribute('style', 'cursor: pointer; margin: 0 2px;');
 		this.urlBar.setAttribute('tooltiptext', require('sdk/l10n').get('name'));
 
 		this.urlBar.addEventListener('click', this.onClick);
@@ -145,15 +265,15 @@
 
 	UrlBar.prototype.addIcon = function(appName) {
 		var
-			icon        = this.document.createElement('image'),
-			url         = typeof appName !== 'undefined' ? 'images/icons/' + appName + '.png' : 'images/icon32.png',
+			icon = this.document.createElement('image'),
+			url = typeof appName === 'undefined' ? 'images/icon32.png' : 'images/icons/' + appName + '.png',
 			tooltipText = ( typeof appName !== 'undefined' ? appName + ' - ' + require('sdk/l10n').get('clickForDetails') + ' - ' : '' ) + require('sdk/l10n').get('name');
 
-		icon.setAttribute('src',         require('sdk/self').data.url(url));
-		icon.setAttribute('class',       'wappalyzer-icon');
-		icon.setAttribute('width',       '16');
-		icon.setAttribute('height',      '16');
-		icon.setAttribute('style',       'margin: 0 1px;');
+		icon.setAttribute('src', require('sdk/self').data.url(url));
+		icon.setAttribute('class', 'wappalyzer-icon');
+		icon.setAttribute('width', '16');
+		icon.setAttribute('height', '16');
+		icon.setAttribute('style', 'margin: 0 1px;');
 		icon.setAttribute('tooltiptext', tooltipText);
 
 		this.get().appendChild(icon);
@@ -168,7 +288,7 @@
 			icons = this.get().getElementsByClassName('wappalyzer-icon');
 
 			if ( icons.length ) {
-				urlBar.get().removeChild(icons[0]);
+				this.get().removeChild(icons[0]);
 			}
 		} while ( icons.length );
 
@@ -176,6 +296,8 @@
 	};
 
 	UrlBar.prototype.destroy = function() {
+		this.panel.destroy();
+
 		this.urlBar.removeEventListener('click', this.onClick);
 
 		this.urlBar.remove();
@@ -197,23 +319,15 @@
 		init: function(callback) {
 			var
 				id,
-				tab,
 				version,
+				win,
 				httpRequestObserver,
 				json = JSON.parse(require('sdk/self').data.load('apps.json'));
 
 			w.log('driver.init');
 
-			panel = new Panel();
-
-			if ( require('sdk/simple-prefs').prefs.urlbar ) {
-				urlBar = new UrlBar(panel);
-			} else {
-				widget = new Widget(panel);
-			}
-
 			try {
-				var version = require('sdk/self').version;
+				version = require('sdk/self').version;
 
 				if ( !require('sdk/simple-storage').storage.version ) {
 					w.driver.goToURL({ url: w.config.websiteURL + 'installed', medium: 'install' });
@@ -231,25 +345,14 @@
 				categoryNames[id] = require('sdk/l10n').get('cat' + id);
 			}
 
-			for each ( tab in require('sdk/tabs') ) {
-				initTab(tab);
-			}
-
-			require('sdk/simple-prefs').on('urlbar', function() {
-				panel = new Panel();
-
-				if ( !require('sdk/simple-prefs').prefs.urlbar ) {
-					urlBar.destroy();
+			require('sdk/windows').browserWindows
+				.on('open', function(win) {
+					windows.push(new Window(win));
+				});
 
-					widget = new Widget(panel);
-				} else {
-					urlBar = new UrlBar(panel);
-
-					widget.get().destroy();
-				}
-
-				w.driver.displayApps();
-			});
+			for each ( win in require('sdk/windows').browserWindows ) {
+				windows.push(new Window(win));
+			}
 
 			httpRequestObserver = {
 				init: function() {
@@ -286,8 +389,6 @@
 			};
 
 			httpRequestObserver.init();
-
-			w.driver.displayApps();
 		},
 
 		goToURL: function(args) {
@@ -296,72 +397,6 @@
 			require('sdk/tabs').open({ url: url, inBackground: typeof args.background !== 'undefined' && args.background });
 		},
 
-		displayApps: function() {
-			var url, count;
-
-			w.log('display apps');
-
-			if ( !require('sdk/tabs').activeTab ) {
-				return;
-			}
-
-			url   = require('sdk/tabs').activeTab.url.replace(/#.*$/, '');
-			count = w.detected[url] ? Object.keys(w.detected[url]).length : 0;
-
-			if ( !panel.get() ) {
-				panel = new Panel();
-
-				if ( require('sdk/simple-prefs').prefs.urlbar ) {
-					urlBar = new UrlBar(panel);
-				} else {
-					widget = new Widget(panel);
-				}
-			}
-
-			if ( typeof tabCache[require('sdk/tabs').activeTab.id] === 'undefined' ) {
-				initTab(require('sdk/tabs').activeTab);
-			}
-
-			tabCache[require('sdk/tabs').activeTab.id].count = count;
-			tabCache[require('sdk/tabs').activeTab.id].appsDetected = w.detected[url];
-
-			if ( require('sdk/simple-prefs').prefs.urlbar ) {
-				urlBar.clear();
-
-				// Add icons
-				if ( count ) {
-					for ( appName in tabCache[require('sdk/tabs').activeTab.id].appsDetected ) {
-						urlBar.addIcon(appName);
-					}
-				} else {
-					urlBar.addIcon();
-				}
-			} else {
-				widget.get().contentURL = require('sdk/self').data.url('images/icon32_hot.png');
-
-				if ( count ) {
-					// Find the main application to display
-					var
-						appName,
-						found = false;
-
-					w.driver.categoryOrder.forEach(function(match) {
-						for ( appName in w.detected[url] ) {
-							w.apps[appName].cats.forEach(function(cat) {
-								if ( cat == match && !found ) {
-									widget.get().contentURL = require('sdk/self').data.url('images/icons/' + appName + '.png'),
-
-									found = true;
-								}
-							});
-						}
-					});
-				}
-			}
-
-			panel.get().port.emit('displayApps', { tabCache: tabCache[require('sdk/tabs').activeTab.id], apps: w.apps, categories: w.categories, categoryNames: categoryNames });
-		},
-
 		ping: function() {
 			var Request = require('sdk/request').Request;
 
@@ -380,6 +415,14 @@
 			}
 		},
 
+		displayApps: function() {
+			var win;
+
+			for each ( win in windows ) {
+				win.displayApps();
+			}
+		},
+
 		categoryOrder: [ // Used to pick the main application
 			 1, // CMS
 			11, // Blog