Apple seeded a the latest beta of OS X 10.8.5 to developers this afternoon with Build 12F36. Devs can pick up the update from the Developer Center or Mac App Store.
The latest beta build comes more than a month after Apple’s last beta for OS X Mountain Lion. The seed notes asks developers to focus on Wi-fi, Graphics, Wake From Sleep, PDF viewing, and Mobile Device Management. Developers will also find a new beta of Safari 6.1 in the Mac Dev Center that’s focused towards testing extensions for compatibility with Safari 6.1.
Source: Apple