Apple today seeded the first test build of OS X 10.9.3 to registered Mac developers, just over a week after releasing OS X 10.9.2. The new beta, build number 13D12, is available through the Software Update mechanism in the Mac App Store as well as through the Mac Dev Center. Apple is currently asking developers to focus on Graphics Drivers and Audio, but there is no word yet on specific fixes and changes included in the update.
