Apple released a Golden Master version of OS X 10.9 Mavericks to developers late Thursday, typically the final release that goes out to consumers.
Apple has also released the GM build of Xcode 5.0.1, which will be used for building Mavericks apps.
Originally expected to be released in September, Apple is now thought to be planning to launch its next-generation operating system at the end of October, people who claim to have knowledge of the company’s plans told 9to5Mac last month.
However, Apple has not confirmed a specific launch date for Mavericks, which comes with hundreds of improvements over OS X 10.8, other than saying it would be available in the fall, alongside a new Mac Pro.
Source: cnet, apple