Angular 2, communication between 2 apps running on the same page [duplicate]

Answer 1

The short answer is you can't.

That being said you can share an instance and use it when bootstrapping both components.

Here is a sample:

var service = new SharedService();

bootstrap(LoginComponent, [
  provide(SharedService, { useValue: service })
]);
bootstrap(ShoppingListComponent, [
  provide(SharedService, { useValue: service })
]);