Apple has released OS X 10.9 Mavericks Developer Preview 6 to developers, with minor improvements. 

The new Mavericks preview, released on Wednesday, arrives two weeks after the fifth Developer Preview with iBooks functionality and a new iPhoto beta was seeded.

OS X Mavericks is set to arrive in the Mac App Store this autumn. See: Mavericks release date

OS X Mavericks has new features, a new look, and a new theme (no more cats). New features include better support for multiple monitors, Finder tabs, improvements to performance and battery consumption, new Maps and iBooks apps and updates to Safari and Calendar, each new beta version brings more details and new improvements to the upcoming operating system.

Apple is believed to be planning a 10 September special event, which could see the launch of two new iPhones, and could also shed some light on when we can expect Mavericks to be released.

See also:

OS X Mavericks: Apple's developers discuss Apple's new love for power users

iOS 7 preview