OS X Mavericks will be a free download

Apple has just announced the latest version of OS X, 10.9 Mavericks, will be available as a free download. In addition to the usual promise of increased speed and efficiency, the update has a number of improvements over 10.8 Mountain Lion, including a more robust notification system (which includes inline replies), better support for multiple monitors and full screen apps, a revamp of Finder, and the addition of iCloud Keychain for saving passwords.