The software is available for download to paid members of the Mac developer program through Apple’s Mac Dev Center or via Software Update in the Mac App Store.
The new OS X Mavericks Developer Preview now for the first time includes iBooks for Mac, a brand new native Mac app Apple promised to include in the final Mavericks release come this Fall…
As noted by MacRumors forum members, the fifth Developer Preview of Mavericks also includes a new iPhoto 9.4.6 beta (build 901.26). Just like iOS 7 Beta 5, major performance enhancements are readily apparent in OS X Mavericks Beta 5.
Apple has also seeded an eighth version of OS X Mountain Lion 10.8.5 Beta (build 12F33) to developers, along with Safari 6.1 Beta 5. That release contains no known issues, indicating that a Gold Master is just around the corner.
Apple plans to offer OS X Mavericks for public consumption this (blockbuster) Fall.
Though the operating system is focused on performance improvements and optimized battery consumption, it comes with a few headline new features such as Finder tabs and tags, improved dual-monitor capabilities in full screen mode and a brand new Maps app that lets you easily beam directions to an iOS device.