The new build, labelled 12D58, has changes to WiFi assets, according to 9To5Mac. It has no known issues, but Apple has urged developers to focus their testing on AirPlay, AirPort, Game Center, graphics drivers, and Safari.
Registered Apple developers can download the OS X 10.8.3 from Apple’s developer portal.
Apple is expected to release the maintenance update for all Mac users in the near future, with the lack of noticeable changes and the large number of seeded builds suggesting that Apple is now adding the finishing touches and ironing out bugs in 10.8.3.
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 is expected that Apple will launch it around July 2013, about a year after it launched Mountain Lion at 2012′s WWDC.