Mac OS X devs, listen up! Apple has just seeded the Mountain Lion Golden Master, and you can grab it right now. The GM status denotes that this is the final version of OS X 10.8 Mountain Lion that will be distributed publicly later this month, barring any debilitating bugs. The build number is 12A269, while the latest Developer Preview update was 12A256. Mountain Lion will sell for $19.99 on the Mac App Store later this month.