Apple has released Mac OS X 10.8.3 Mountain Lion build 12D76 to developers, whereas 12D74 build was released by the end of last month. This time developers are asked to focus over AirPlay, AirPort, Game Center, Graphics Drivers, and Safari in OS X 10.8.3 Mountain Lion build 12D76.
Registered Apple developers can download OS X 10.8.3 Mountain Lion build 12D76 via Mac Dev Center.