The new build, labelled 12D50, was released on Tuesday, just over two weeks after Apple seeded the previous 12D44 build to developers.
The build comes with no known issues, and just minor changes to the operating system update pre-release. In fact, the build notes are identical to the previous two builds seeded to developers in December, hinting that the public release could be imminent.
Developers have been advised to focus their testing on AirPlay, AirPort, Game Center, Graphics Drivers and Safari.
In December, Apple released an update to the Mac OS X 10.8.3 Mountain Lion beta just two days after the previous build was seeded to developers, suggesting that there was a security flaw or oversight in the first build.
Looking ahead, speculation suggests that Apple may be considering the name ‘Lynx’ for its next Mac OS X, which is expected to be released later this year. The new operating system could introduce Maps and Siri integration to the Mac, reports say.
OS X 10.9 has already been appearing in analytics logs across the web, and it is expected that Apple will launch it around July 2013, about a year after it launched Mountain Lion.