Push Notifications on your Mac
from MacRumors.

OS X Mavericks (10.9) introduced a new feature that allows users to subscribe to "push" notifications from any website. Pushes show up as notification badges on the top right of your screen and can be used to be instantly notified when there are new MacRumors stories.

In order to subscribe, you need OS X Mavericks (10.9) or later and Safari. Configure your settings below.

Push subscriptions are easy to opt-in to and easy to unsubscribe from using Safari's preferences.