updated 09:12 pm EDT, Wed April 9, 2014
Latest release comes with minor tweaks to new features
On Wednesday, Apple issued its sixth beta of the forthcoming maintenance release, 10.9.3. As with last week, developers are asked to focus on graphics drivers, audio, Mail, Safari and the newly-restored local syncing of contacts and calendar data over USB through iTunes. In earlier versions of iTunes 11, syncing was exclusively handled by iCloud. The new build, 13D38, is only five revisions higher than the previous release, suggesting that a public debut is likely to happen relatively soon.
The latest built contains no new issues. In addition to the return of local syncing for those who can't or don't want to use iCloud syncing, 10.9.3 also promises a bonus for those on the latest MacBook Pros -- pixel-doubled scaling for 4K monitors. The feature will effectively bring "Retina" screen quality to existing 4K monitor support, as well as expand the number of potential brands of monitor supported. The pixel-doubling will likely expand to other machines in future releases.
The update is available through the Mac App Store's Software Update for developer accounts, or Apple's dedicated Mac developer portal.