On Tuesday, Apple released the latest build of OS X 10.9.3, designated ‘Build 13D43’. For this build, developers are being asked to focus their efforts on testing Graphics Drivers, Audio, Mail, Contacts and Calendar sync over USB in iTunes, and Safari. 10.9.3 also adds support for 4K displays, which offers improved readability and 60Hz output from a Retina display MacBook Pro.
Build releases are appearing closer together now, this one only a week after the previous seed. This is typically a sign that Apple is close to locking the update down in preparation for its release, so be on the lookout for 10.9.3 showing up in the App Store soon. Per usual, we recommend that you make sure to backup your Macs before applying the update, and running Repair Permissions from Disk Utility before and after the update is a good idea too.