Apple on Tuesday released the thirteenth beta of OS X Mountain Lion 10.8.3 to developers and its employees, indicating that the public release will arrive soon.

MacRumors reports that the new build, labelled 12D76, has no listed changes, is thought to have been seeded to Apple employees as well as developers, which suggests that the new beta iteration is the final version of the update.

The first beta version of the Mountain Lion 10.8.3 update was released back in November, and there have been regular new builds seeded to developers since. We've been expecting the 10.8.3 update to be released to the public since as far back as January, when developers began to report that no known issues or major changes had been made to the beta builds. However, the final update was still nowhere to be seen, with some people suggesting that Apple is hiding secret details about iOS 7, Apple's next mobile operating system.

But it looks like thirteen could be the lucky number, with reports that employees have been given the beta suggesting that the public update really is imminent this time.

Apple has been asking developers to focus their testing on AirPlay, AirPort, Game Center, Graphics Drivers and Safari.

Looking ahead, speculation suggests that Apple may be considering the name 'Lynx' for its next Mac OS X, 10.9, 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 been appearing in analytics logs across the web, and it is expected that Apple will launch the operating system around July 2013, possibly at its Worldwide Developers Conference (WWDC). Apple launched Mountain Lion at WWDC in July 2012, but gave preview versions of the software to select reporters ahead of the event, who published hands-on reviews in February 2012.

SEE: January sees OS X 10.9 traffic spike, Apple announcement imminent?

This week, TechCrunch and Business Insider have both reported a rapid increase in data from OS X 10.9 appearing in their analytics logs, indicating that the Apple is gearing up to unveil its new operating system soon.

See also:

US Mac sales make small rebound

Configuring Mountain Lion's Users and Groups

Opinion: What's wrong with the Mountain Lion interface

Microsoft Windows 8 versus OS X Mountain Lion