Just as Apple promised, its OS X Mavericks update is now available as a digital download from the Mac App Store. The operating system upgrade weighs in at 5.29GB, so you'll want to set aside some time for the installation process. Thankfully, Apple is giving plenty of its existing customers the chance to move up to Mavericks at no cost. On stage during its event today, software chief Craig Federighi announced that Mavericks is a free download to users of OS X Snow Leopard and later. To get started with Apple's latest desktop OS, head to the Mac App Store now. Updated versions of the company's iWork and iLife suite of apps are also expected to be released before the day's end.