Apple today seeded build 12F17 of OS X 10.8.5 to developers, offering a third version of the next Mac operating system update for testing. The release comes one week after the appearance of the previous beta of OS X 10.8.5, build 12F13.

12f17
As with previous betas, the update comes with no known issues and can be downloaded via Apple's Developer Page or through the software update tool in the Mac App Store.

Testing on OS X 10.8.5 comes as Apple is also continuing work on its next major version of OS X, Mavericks. Apple has already seeded two developer previews of OS X Mavericks and has announced that it will launch the new operating system to the public this fall.

Top Rated Comments

WildCowboy Avatar
164 months ago
Can any one explain to me why they are still doing this instead of putting extra work in Mavericks? Not that it bothers me, just asking

Mavericks isn't coming for months, and there are things in Mountain Lion that need fixing.
Score: 14 Votes (Like | Disagree)
beelzebubba Avatar
164 months ago
Can any one explain to me why they are still doing this instead of putting extra work in Mavericks? Not that it bothers me, just asking

Because many people still run ML and will even after Mavericks comes out. ML will likely be the end of the line for some older Macs and Apple has done fairly well in supporting legacy machines even past the five year end of life.
Score: 8 Votes (Like | Disagree)
laflores Avatar
164 months ago
Can any one explain to me why they are still doing this instead of putting extra work in Mavericks? Not that it bothers me, just asking

Because otherwise, people would start crying because "apple doesn't care about mountain lion any more" and some people will complain that mavericks is a piece of **** and they rather stay with snow leopard...
Score: 8 Votes (Like | Disagree)
rdlink Avatar
164 months ago
Gonna miss those cats when they're gone.
Score: 7 Votes (Like | Disagree)
iBug2 Avatar
164 months ago
(not trolling)

first time that safari has ever been snappier for me....running rMBP.....but it might also just be because safari in mavs is horrible

Are you kidding me? Safari 7.0 finally solves the memory issue which was introduced in 5.1 where when you open many tabs, web process just crashes. 7.0 does not have that, the single most annoying Safari bug in 2 years being solved finally.
Score: 5 Votes (Like | Disagree)
darkknight14 Avatar
164 months ago
Gonna miss those cats when they're gone.

Me too, every time I look at that new wave background it makes me want to go for a p***
Score: 4 Votes (Like | Disagree)

Popular Stories

Aston Martin CarPlay Ultra Screen

Apple's CarPlay Ultra to Expand to These Vehicle Brands Later This Year

Sunday February 1, 2026 10:08 am PST by
Last year, Apple launched CarPlay Ultra, the long-awaited next-generation version of its CarPlay software system for vehicles. Nearly nine months later, CarPlay Ultra is still limited to Aston Martin's latest luxury vehicles, but that should change fairly soon. In May 2025, Apple said many other vehicle brands planned to offer CarPlay Ultra, including Hyundai, Kia, and Genesis. In his Powe...
Apple Logo Black

Apple's Next Launch is 'Imminent'

Sunday February 1, 2026 12:31 pm PST by
The calendar has turned to February, and a new report indicates that Apple's next product launch is "imminent," in the form of new MacBook Pro models. "All signs point to an imminent launch of next-generation MacBook Pros that retain the current form factor but deliver faster chips," Bloomberg's Mark Gurman said on Sunday. "I'm told the new models — code-named J714 and J716 — are slated...
Apple MacBook Pro M4 hero

New MacBook Pros Reportedly Launching Alongside macOS 26.3

Sunday February 1, 2026 5:42 am PST by
Apple is planning to launch new MacBook Pro models with M5 Pro and M5 Max chips alongside macOS 26.3, according to Bloomberg's Mark Gurman. "Apple's faster MacBook Pros are planned for the macOS 26.3 release cycle," wrote Gurman, in his Power On newsletter today. "I'm told the new models — code-named J714 and J716 — are slated for the macOS 26.3 software cycle, which runs from...
iOS 26

iOS 26.3 and iOS 26.4 Will Add These New Features to Your iPhone

Tuesday February 3, 2026 7:47 am PST by
We are still waiting for the iOS 26.3 Release Candidate to come out, so the first iOS 26.4 beta is likely still at least a week or two away. Following beta testing, iOS 26.4 will likely be released to the general public in March or April. Below, we have recapped known or rumored iOS 26.3 and iOS 26.4 features so far. iOS 26.3 iPhone to Android Transfer Tool iOS 26.3 makes it easier...
14 inch MacBook Pro Keyboard

Apple Changes How You Order a Mac

Saturday January 31, 2026 10:51 am PST by
Apple recently updated its online store with a new ordering process for Macs, including the MacBook Air, MacBook Pro, iMac, Mac mini, Mac Studio, and Mac Pro. There used to be a handful of standard configurations available for each Mac, but now you must configure a Mac entirely from scratch on a feature-by-feature basis. In other words, ordering a new Mac now works much like ordering an...