Mac OS X 10.8.5

Mac OS X 10.8.5 was an update to Mac OS X 10.8 released on September 12, 2013 with a supplemental update on October 3, 2013. It had the following features:
 * Fixes an issue that may prevent Mail from displaying messages
 * Improves AFP file transfer performance over 802.11ac Wi-Fi
 * Resolves an issue that may prevent a screen saver from starting automatically
 * Improves Xsan reliability
 * Improves reliability when transferring large files over Ethernet
 * Improves performance when authenticating to an Open Directory server
 * Addresses an issue that prevented a smart card from unlocking preference panes in System Preferences
 * Contains the improvements included in MacBook Air (Mid 2013) Software Update 1.0

About the OS X v10.8.5 Supplemental Update
The OS X v10.8.5 Supplemental Update is recommended for all users running OS X Mountain Lion v10.8.5. This update:
 * Resolves an issue that may prevent certain applications from using the FaceTime HD camera on MacBook Air (mid-2013) systems
 * Fixes an issue that may cause external drives to be ejected after the computer goes to sleep
 * Addresses an issue that may prevent HDMI audio from working after waking from sleep
 * Fixes an issue that may prevent certain USB Bluetooth adapters from working

External References
Apple: About the OS X 10.8.5 Update