Apple Seeds OS X Mavericks 10.9.2 Build 13C39 to Developers
The update is available to registered developers through the Software Update mechanism in the Mac App Store as well as through the Mac Dev Center.
The first seed of OS X 10.9.2 introduced FaceTime Audio to the Mac and asked developers to focus testing on Mail, Messages, VPN, Graphics Drivers, and VoiceOver. The second build allows Mac users to block people on iMessage and FaceTime as can be done in iOS 7.
Apple has also seeded Safari 7.0.2 for Mavericks and Safari 6.1.2 for Lion/Mountain Lion, asking developers to focus on General Website Compatibility, Accessibility, AutoFill features, Printing and Emailing from Reader, Dragging Tabs Between Monitors, and Extension Compatibility.