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
165 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
165 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
165 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
165 months ago
Gonna miss those cats when they're gone.
Score: 7 Votes (Like | Disagree)
iBug2 Avatar
165 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
165 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

maxresdefault

Apple Shows Off a Key Reason to Upgrade to the iPhone 17

Saturday February 7, 2026 9:26 am PST by
Apple today shared an ad that shows how the upgraded Center Stage front camera on the latest iPhones improves the process of taking a group selfie. "Watch how the new front facing camera on iPhone 17 Pro takes group selfies that automatically expand and rotate as more people come into frame," says Apple. While the ad is focused on the iPhone 17 Pro and iPhone 17 Pro Max, the regular iPhone...
wwdc sans text feature

Apple Rumored to Announce New Product on February 19

Thursday February 5, 2026 12:22 pm PST by
Apple plans to announce the iPhone 17e on Thursday, February 19, according to Macwelt, the German equivalent of Macworld. The report, citing industry sources, is available in English on Macworld. Apple announced the iPhone 16e on Wednesday, February 19 last year, so the iPhone 17e would be unveiled exactly one year later if this rumor is accurate. It is quite uncommon for Apple to unveil...
apple wallet drivers license feature iPhone 15 pro

Apple Says These 7 U.S. States Plan to Offer iPhone Driver's Licenses

Monday February 9, 2026 6:24 am PST by
In select U.S. states, residents can add their driver's license or state ID to the Apple Wallet app on the iPhone and Apple Watch, and then use it to display proof of identity or age at select airports and businesses, and in select apps. The feature is currently available in 13 U.S. states and Puerto Rico, and it is expected to launch in at least seven more in the future. To set up the...
Finder Siri Feature

Why Apple's iOS 26.4 Siri Upgrade Will Be Bigger Than Originally Promised

Friday February 6, 2026 3:06 pm PST by
In the iOS 26.4 update that's coming this spring, Apple will introduce a new version of Siri that's going to overhaul how we interact with the personal assistant and what it's able to do. The iOS 26.4 version of Siri won't work like ChatGPT or Claude, but it will rely on large language models (LLMs) and has been updated from the ground up. Upgraded Architecture The next-generation...
14 inch MacBook Pro Keyboard

New MacBook Pros Could Now Arrive in March

Sunday February 8, 2026 6:02 am PST by
New MacBook Pro models with the M5 Pro and M5 Max chips could arrive as soon as Monday, March 2, according to Bloomberg's Mark Gurman. In today's "Power On" newsletter, Gurman said that the release of new MacBook Pro models is tied to the release of macOS Tahoe 26.3. The launch is said to be slated for as early as the week of March 2. He added that the M4 Pro and M4 Max models on sale today...