Got a six-year old Mac? You’re entitled to a free operating system update.

Almost overlooked in the launch of the iPad Air was news that OS X Mavericks (also known as version 10.9 of the OS) is available for no charge for Macs running Snow Leopard, Lion or Mountain Lion (in other words version 10.7, 10.7 and 10.8).

Mavericks has more than 200 new features, says Apple, including iBooks and Maps from the iPad, a new version of the Safari browser, enhanced multi-display support, and Finder Tabs and Tags for organizing files.

Other new capabilities include a streamlined Calendar estimates travel time between appointments; iCloud Keychain for safely storing Website usernames, passwords and credit card numbers and pushes them to mobile devices so users don’t have to remember them; and interactive Notifications that allow users to respond to messages without leaving an application.

It also improves battery life.

As Computerworld U.S. notes, the free upgrade isn’t much of a saving: Mac users paid only $20 for the last one, Mountain Lion, in 2012.

But industry analysts saw the move as another way Apple is saying that the real way it makes money is on the hardware.

For a full list of Macs that qualify for Mavericks, click here.

To read a fuller account of the announcement click here. To read more details about Mavericks click here.