OS X 10.9

OS X version 10.9, also known as "Mavericks", 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.

The update places emphasis on battery life, Finder enhancements, other enhancements for power users, and continued iCloud integration, as well as bringing more of Apple's iOS apps to the OS X platform. Mavericks marks the beginning of a change in the naming scheme of OS X, departing from the use of big cats and moving to names based on places in California. Following the new naming scheme, the current version of the operating system is named Mavericks, after the surfing location in California. The new naming scheme also removes the "Mac" prefix from the name.

New and changed features
The following is a list of features that differ from previous releases of OS X:
 * Improved multiple display support: The menu bar and the Dock can be accessed on each display; Apple TV can be used as an external display.
 * Mission Control has been updated to organize and switch between Desktop workspaces independently between multiple displays.
 * Finder enhancements, including tabs, fullscreen support, and document tags.
 * Added new iBooks application.
 * Added new Maps application.
 * Calendar enhancements.
 * Safari browser enhancements.
 * iCloud Keychain sync.
 * Notification Center enhancements.
 * Some skeuomorphs, such as the leather texture in Calendar and the book-like appearance of Contacts, have been removed from the UI.
 * Timer coalescing, which enhances energy efficiency by reducing CPU usage by up to 72%.
 * App Nap, which sleeps apps that are not currently visible.
 * Compressed Memory, which automatically compresses data from inactive apps when approaching maximum memory capacity.
 * Server Message Block version 2 (SMB2) is now the default protocol for sharing files.
 * LinkedIn sharing integration.
 * OpenGL 4.1 Core Profile.
 * OpenCL 1.2.
 * USB syncing of calendar, contacts and other information to iOS devices has been removed, instead requiring the use of iCloud.
 * Some system alerts, such as low battery and removal of drives without ejecting, have been moved to Notification Center.