OS X Mavericks (version 10.9) is the tenth major release of OS X, Apple Inc.'s desktop and server operating system for Macintosh computers. OS X Mavericks was announced on June 10, 2013, at WWDC 2013, and was released on October 22, 2013, as a free update through the Mac App Store worldwide.The update emphasized battery life, Finder improvements, other improvements for power users, and continued iCloud integration, as well as bringing more of Apple's iOS apps to OS X.