Apple today seeded build 13D55 of OS X 10.9.3 to developers, just over a week after releasing the eighth OS X beta, build 13D45a, and nearly two months after the first 10.9.3 beta



From MacRumors:

The beta is available through the Software Update mechanism in the Mac App Store as well as through the Mac Dev Center. Apple continues to ask developers to focus on Graphics Drivers, Audio, Mail, Contacts and Calendar sync over USB in iTunes, and Safari.

  Apple Seeds OS X Mavericks 10.9.3 Build 13D55 to Developers