Just under two weeks after releasing OS X Mavericks 10.9.2, Apple has seeded the first beta of OS X Mavericks version 10.9.3 to developers. The build number is 13D12. Like its predecessor, it is likely that 10.9.3 focuses on additional bug fixes. Apple asks developers to focus on Graphics Drivers and Audio during testing. We’ll update this post if new features are discovered.

Update: 10.9.3 builds in support for running 4K monitors at Retina resolution. All of the details here

Thanks, D!