One of the new features OS X Mavericks - push-notifications for sites with new content will immediately appear on the Mac desktop. Today, the developer Connor LaCombe, introduced a new service Pronto Push, allowing a native push-notification for any RSS-stream.
Rather than wait for the developers of your favorite sites will add support for the push, you can now be notified using the Pronto Push. To do this, you need to register with the service and add the sites you want to track. Manage subscriptions and adding new, happening through the web interface - installing the application on a computer is not required. Also it claims to support multiple computers to one account Pronto Push.
The initial configuration will need to do it in Safari 7, but then when you click on the notification, they will be opened in your main browser. Notifications come instantly, as the new post will only appear on the site. Besides the usual RSS-feeds you can add Facebook, Twitter. For Facebook is important because of its built-in notification is usually delayed or do not reach.
Service Pronto Push free and is currently in beta testing. To use it, you do not have to be installed OS X Mavericks.