OS X Mavericks (version 10.9) is the 11th major release of OS X, Apple Inc's desktop and server operating system for Macintosh computers. OS X Yosemite was announced on June 10, 2013 at WWDC 2013, and was released in October of 2014.(please update below) The update places emphasis on battery life, Finderenhancements, other enhancements for power users, and continued iCloud integration, as well as bringing more of Apple's iOS apps to the OS X platform.