Hot on the heels of iOS 7 beta 2, Apple has also just released OS X 10.9 Mavericks Developer Preview 2. If you’re running a beta version of Mavericks, you can grab the update via the Mac App Store.
The build number for the updated version is 13A497d. It is accompanied by new seeds of Xcode 5 and OS X Server as well. Beta software, is as always, under NDA and should only be downloaded and used by developers. The public release of OS X Mavericks is slated for this fall.