Apple today seeded build 12D76 of OS X Mountain Lion to developers, marking the twelfth beta iteration of the newest version of Mountain Lion. 10.8.3 was first seeded to developers in November of 2012.

10.8.3

Build 12D76 comes less than a week after build 12D74 and features no listed changes. Registered developers can download the update on Apple’s Developer Page.

Update: We've heard that Apple has seeded this version of OS X 10.8.3 to employees, suggesting that it is the final version of the software and is likely to be released to the public in the very near future.

This post originally referred to Build 12D76 as the thirteenth developer seed of OS X 10.8.3 when it was actually the twelfth seed.

Top Rated Comments

MisterKeeks Avatar
167 months ago
The devs at Apple are watching this thread and giggling.
Score: 20 Votes (Like | Disagree)
Makosuke Avatar
167 months ago
Leaving aside the pathological desire to update any and all software constantly, I consider thoroughly tested software fundamentally better.

So if Apple really is hammering 10.8.3 this hard to make sure it's clean, I consider that a good thing.

(One could of course argue that they should just let it loose and fix the remaining issues in 10.8.4, but are there any bugs that 10.8.3 is fixing that are so egregious that it needs to come out NOW, thorough testing be damned?)

Does this hold the record for longest run between point iterations of a current-version OSX, though? It's certainly the most betas with no known issues I can remember seeing.
Score: 19 Votes (Like | Disagree)
mogwat Avatar
167 months ago
July, 2022. OSX 15.4.7 released and OSX 10.8.3 beta 78....
Score: 18 Votes (Like | Disagree)
Peace Avatar
167 months ago
Apple changes one line of code...

Pushes new beta
There are over 50 apps that have been updated in this seed.

Not to mention system stuff.
Score: 13 Votes (Like | Disagree)
nfl46 Avatar
167 months ago
Is this a joke? Must be...
Score: 12 Votes (Like | Disagree)
HMI Avatar
167 months ago
Change Log:

10.8.2
SafariEngineSnappyMode = 0

10.8.3
SafariEngineSnappyMode = 1
Score: 10 Votes (Like | Disagree)

Popular Stories

iOS 26

15 New Things Your iPhone Can Do in iOS 26.2

Friday December 5, 2025 9:40 am PST by
Apple is about to release iOS 26.2, the second major point update for iPhones since iOS 26 was rolled out in September, and there are at least 15 notable changes and improvements worth checking out. We've rounded them up below. Apple is expected to roll out iOS 26.2 to compatible devices sometime between December 8 and December 16. When the update drops, you can check Apple's servers for the ...
iPhone 14 Pro Dynamic Island

iPhone 18 Pro Leak Adds New Evidence for Under-Display Face ID

Monday December 8, 2025 4:54 am PST by
Apple is actively testing under-screen Face ID for next year's iPhone 18 Pro models using a special "spliced micro-transparent glass" window built into the display, claims a Chinese leaker. According to "Smart Pikachu," a Weibo account that has previously shared accurate supply-chain details on Chinese Android hardware, Apple is testing the special glass as a way to let the TrueDepth...
iOS 26

Apple Seeds Second iOS 26.2 Release Candidate to Developers and Public Beta Testers

Monday December 8, 2025 10:18 am PST by
Apple today seeded the second release candidate version of iOS 26.2 to developers and public beta testers, with the software coming one week after Apple seeded the first RC. The release candidate represents the final version iOS 26.2 that will be provided to the public if no further bugs are found. Registered developers and public beta testers can download the betas from the Settings app on...
iPhone 17 Pro Cosmic Orange

10 Reasons to Wait for Next Year's iPhone 18 Pro

Monday December 1, 2025 2:40 am PST by
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models at the same time, which is why we often get rumored features months ahead of launch. The iPhone 18 series is no different, and we already have a good idea of what to expect for the iPhone 18 Pro and iPhone 18 Pro Max. One thing worth...
Johny Srouji

Apple's Chipmaking Chief Johny Srouji Responds to Report About Him Potentially Leaving

Monday December 8, 2025 9:23 am PST by
Apple's chipmaking chief Johny Srouji has reportedly indicated that he plans to continue working for the company for the foreseeable future. "I love my team, and I love my job at Apple, and I don't plan on leaving anytime soon," said Srouji, in a memo obtained by Bloomberg's Mark Gurman. Here is Srouji's full memo, as shared by Bloomberg:I know you've been reading all kind of rumors and...
Johny Srouji

Apple Chip Chief Johny Srouji Could Be Next to Go as Exodus Continues

Sunday December 7, 2025 10:41 am PST by
Apple's senior vice president of hardware technologies Johny Srouji could be the next leading executive to leave the company amid an alarming exodus of leading employees, Bloomberg's Mark Gurman reports. Srouji apparently recently told CEO Tim Cook that he is "seriously considering leaving" in the near future. He intends to join another company if he departs. Srouji leads Apple's chip design ...
Intel Inside iPhone Feature

Apple's Return to Intel Rumored to Extend to iPhone

Friday December 5, 2025 10:08 am PST by
Intel is expected to begin supplying some Mac and iPad chips in a few years, and the latest rumor claims the partnership might extend to the iPhone. In a research note with investment firm GF Securities this week, obtained by MacRumors, analyst Jeff Pu said he and his colleagues "now expect" Intel to reach a supply deal with Apple for at least some non-pro iPhone chips starting in 2028....
google pixel 10

Switching Between iPhone and Android Will Get Easier With New Apple and Google Collaboration

Monday December 8, 2025 11:10 am PST by
Apple and Google are teaming up to make it easier for users to switch between iPhone and Android smartphones, according to 9to5Google. There is a new Android Canary build available today that simplifies data transfer between two smartphones, and Apple is going to implement the functionality in an upcoming iOS 26 beta. Apple already has a Move to iOS app for transferring data from an Android...
Foldable iPhone 2023 Feature 1

Apple to Make More Foldable iPhones Than Expected

Tuesday December 9, 2025 9:59 am PST by
Apple has ordered 22 million OLED panels from Samsung Display for the first foldable iPhone, signaling a significantly larger production target than the display industry had previously anticipated, ET News reports. In the now-seemingly deleted report, ET News claimed that Samsung plans to mass-produce 11 million inward-folding OLED displays for Apple next year, as well as 11 million...
Apple Fitness Plus expansion hero

Apple Fitness+ Coming to 28 New Regions With Digital Voice Dubbing

Monday December 8, 2025 6:19 am PST by
Apple today announced that Fitness+ is expanding to 28 new markets on December 15 in the service's largest international rollout since launch, accompanied by new language dubbing and a K-Pop music genre. Apple Fitness+ will become available in Chile, Hong Kong, India, the Netherlands, Singapore, Taiwan, and additional regions on December 15, with Japan scheduled to follow early next year....