diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..c2658d7d
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+node_modules/
diff --git a/package.json b/package.json
new file mode 100644
index 00000000..85e70f85
--- /dev/null
+++ b/package.json
@@ -0,0 +1,25 @@
+{
+  "name": "single-spa",
+  "version": "1.0.0",
+  "description": "Multiple applications, one page",
+  "main": "dist/single-spa.js",
+  "scripts": {
+    "build": "babel src/single-spa.js --out-file dist/single-spa.js"
+  },
+  "keywords": [
+    "single",
+    "page",
+    "application",
+    "spa",
+    "multiple",
+    "lifecycle"
+  ],
+  "author": "Joel Denning",
+  "license": "MIT",
+  "dependencies": {
+    "es6-module-loader": "0.17.7"
+  },
+  "devDependencies": {
+    "babel": "^5.8.23"
+  }
+}
diff --git a/src/single-spa.js b/src/single-spa.js
new file mode 100644
index 00000000..e3e56475
--- /dev/null
+++ b/src/single-spa.js
@@ -0,0 +1,161 @@
+let appLocationToApp = {};
+let unhandledRouteHandlers = [];
+let mountedApp;
+const nativeAddEventListener = window.addEventListener;
+
+window.singlespa = function(element) {
+	window.history.pushState(undefined, '', element.getAttribute('href'));
+	setTimeout(function() {
+		triggerAppChange();
+	}, 10);
+	return false;
+}
+
+export function declareChildApplication(appLocation, activeWhen) {
+	if (typeof appLocation !== 'string' || appLocation.length === 0)
+		throw new Error(`The first argument must be a non-empty string 'appLocation'`);
+	if (typeof activeWhen !== 'function')
+		throw new Error(`The second argument must be a function 'activeWhen'`);
+	if (appLocationToApp[appLocation])
+		throw new Error(`There is already an app declared at location ${appLocation}`);
+
+	appLocationToApp[appLocation] = {
+		appLocation: appLocation,
+		activeWhen: activeWhen,
+		parentApp: mountedApp ? mountedApp.appLocation : null
+	};
+
+	triggerAppChange();
+}
+
+export function addUnhandledRouteHandler(handler) {
+	if (typeof handler !== 'function') {
+		throw new Error(`The first argument must be a handler function`);
+	}
+	unhandledRouteHandlers.push(handler);
+}
+
+export function updateApplicationSourceCode(appName) {
+	if (!appLocationToApp[appName]) {
+		throw new Error(`No such app '${appName}'`);
+	}
+	let app = appLocationToApp[appName];
+	app.lifecycleFunctions.activeApplicationSourceWillUpdate().then(() => {
+		//TODO reload the app
+		app.lifecycleFunctions.activeApplicationSourceWasUpdated();
+	});
+}
+
+function loadAppForFirstTime(appLocation) {
+	return new Promise(function(resolve, reject) {
+		System.import(appLocation).then(function(restOfApp) {
+			if (restOfApp.default) {
+				restOfApp = restOfApp.default;
+			}
+			registerApplication(appLocation, restOfApp);
+			let app = appLocationToApp[appLocation];
+			app.entryWillBeInstalled().then(() => {
+				System.import(app.entry).then(() => {
+					resolve();
+				})
+			})
+		})
+	})
+}
+
+function registerApplication(appLocation, partialApp) {
+	let app = appLocationToApp[appLocation];
+	for (propertyName in partialApp) {
+		app[propertyName] = partialApp[propertyName];
+	}
+	app.hashChangeFunctions = [];
+	app.popStateFunctions = [];
+}
+
+nativeAddEventListener('popstate', triggerAppChange);
+
+function triggerAppChange() {
+	let newApp = appForCurrentURL();
+	if (!newApp) {
+		unhandledRouteHandlers.forEach((handler) => {
+			handler(mountedApp);
+		});
+	}
+
+	if (newApp !== mountedApp) {
+		let appWillUnmountPromise = mountedApp ? mountedApp.applicationWillUnmount() : new Promise((resolve) => resolve());
+
+		appWillUnmountPromise.then(function() {
+			let appLoadedPromise = newApp.entry ? new Promise((resolve) => resolve()) : loadAppForFirstTime(newApp.appLocation);
+			appLoadedPromise.then(function() {
+				let appMountedPromise = new Promise(function(resolve) {
+					if (mountedApp) {
+						mountedApp.unmountApplication().then(() => {
+							finishUnmountingApp(mountedApp);
+							resolve();
+						});
+					} else {
+						resolve();
+					}
+				});
+				appMountedPromise.then(function() {
+					newApp.applicationWillMount().then(function() {
+						appWillBeMounted(newApp);
+						newApp.mountApplication().then(function() {
+							mountedApp = newApp;
+						});
+					})
+				});
+			})
+		})
+	}
+}
+
+function appForCurrentURL() {
+	let appsForCurrentUrl = [];
+	for (let appName in appLocationToApp) {
+		let app = appLocationToApp[appName];
+		if (app.activeWhen(window.location)) {
+			appsForCurrentUrl.push(app);
+		}
+	}
+	switch (appsForCurrentUrl.length) {
+		case 0:
+			return undefined;
+		case 1:
+			return appsForCurrentUrl[0];
+		default:
+			appNames = appsForCurrentUrl.map((app) => app.name);
+			throw new Error(`The following applications all claim to own the location ${window.location.href} -- ${appnames.toString()}`)
+	}
+}
+
+function finishUnmountingApp(app) {
+	app.hashChangeFunctions.forEach((hashChangeFunction) => {
+		window.removeEventListener('hashchange', hashChangeFunction);
+	});
+	app.popStateFunctions.forEach((popStateFunction) => {
+		window.removeEventListener('popstate', popStateFunctions);
+	});
+	//TODO clean up the dom???
+}
+
+function appWillBeMounted(app) {
+	app.hashChangeFunctions.forEach((hashChangeFunction) => {
+		nativeAddEventListener('hashchange', hashChangeFunction);
+	});
+	app.popStateFunctions.forEach((popStateFunction) => {
+		nativeAddEventListener('popstate', popStateFunctions);
+	});
+}
+
+window.addEventListener = function(name, fn) {
+	if (mountedApp) {
+		if (name === 'popstate') {
+			mountedApp.popStateFunctions.push(fn);
+		} else if (name === 'hashchange') {
+			mountedApp.hashChangeFunctions.push(fn);
+		}
+		nativeAddEventListener.apply(this, arguments);
+	}
+}