Today, Apple has seeded OS X Mountain Lion 10.8.5 build 12F36 to developers. The update is available via Software Update in the Mac App Store and it is available on the Mac Dev Center. The update comes a day following the release of OS X Mavericks Developer Preview 7 and nearly a month following the previous 10.8.5 seed. A new Safari 6.1 seed is also available for developers. Thanks, D!