Softwareupdate
Apple today seeded build 12D58 of OS X Mountain Lion 10.8.3 to developers, marking the seventh beta iteration of the newest version of Mountain Lion. 10.8.3 was first seeded to developers in November.

Build 12D58 comes a week after build 12D54, and like the previous build, contains no known issues or features. Build 12D54 brought significant changes to WiFi, and asked developers to focus on testing AirPlay, AirPort, Game Center, Graphics Drivers, and Safari.

9to5Mac notes that the new build again contains significant changes to WiFi, but additional changes are unknown. Registered developers can download the update on Apple’s Developer Page.

This post originally referred to Build 12D58 as the eighth developer seed of OS X 10.8.3 when it was actually the seventh seed.

Top Rated Comments

iBug2 Avatar
167 months ago
I don't get all these beta's? Are Apple actually listening and at least TRYING to fix the damn slow shutdown bug and options having to be launched twice from settings such as desktop background?

The slow shutdown is not really a "bug". It's an inconvenience for some people who have it. Apple has a lot more serious issues to fix during these beta tests. Something like a slow shutdown would be on the bottom of their list.
Score: 10 Votes (Like | Disagree)
daneoni Avatar
167 months ago
Agreed, but a a simple and easy to fix bug like this not being fixed for a quarter of a year is starting to produce a painful impression.

Mac sales going down should be a warning - do your homework Apple!
Mac sales going down is due to a general decline in PC sales. Thanks to the post-PC era. Not because of some random, minor, bug in an OS.
Score: 9 Votes (Like | Disagree)
tywebb13 Avatar
167 months ago
The installer includes a feature list:

The 10.8.3 update is recommended for all OS X Mountain Lion users and includes features and fixes that improve the stability, compatibility, and security of your Mac, including the following:
• The ability to redeem iTunes gift cards in the Mac App Store using your Mac's built-in camera
• Boot Camp support for installing Windows 8
• Boot Camp support for Macs with a 3TB hard drive
• A fix for an issue that may cause Logic Pro to become unresponsive when using certain plug-ins
• A fix for an issue that may cause audio to stutter on 2011 iMacs
• Includes Safari 6.0.3
Score: 8 Votes (Like | Disagree)
LlamaLarry Avatar
167 months ago
I am always a surprised to see people complaining about slow shutdown (and I assume reboots). I guess I just don't shutdown/reboot as often as some folks; must be a Windows convert thing as I am pretty sure older Mac (and other *nix) don't shutdown OR reboot just for fun or often enough to care how long it takes.

It wasn't that long ago that I remember people complaining that rebooting to upgrade Safari or other system updates was literally like the end of the world because some folks had so much stuff open for their workflows they could not handle having to launch them all manually... Now OSX offers you the choice to have it do that for you as well.
Score: 5 Votes (Like | Disagree)
The Bulge Avatar
167 months ago
The slow shutdown is not really a "bug". It's an inconvenience for some people who have it. Apple has a lot more serious issues to fix during these beta tests. Something like a slow shutdown would be on the bottom of their list.

It must be fixed and as a user i don't really care how or do you want the next generation Macs with OS X to shut down in 30 seconds out of the box because it's low priority?
Score: 4 Votes (Like | Disagree)
iBug2 Avatar
167 months ago
Agreed, but a a simple and easy to fix bug like this not being fixed for a quarter of a year is starting to produce a painful impression.

Mac sales going down should be a warning - do your homework Apple!

Why do you assume it's an easy fix? Maybe it isn't.
Score: 4 Votes (Like | Disagree)

Popular Stories

Tim Cook WWDC 2018

Report: Tim Cook to Step Down as Apple CEO 'as Soon as Next Year'

Saturday November 15, 2025 2:40 pm PST by
Apple is preparing for Tim Cook to step down as CEO of the company "as soon as next year," according to the Financial Times. The company's board of directors and senior executives "recently intensified preparations for Cook to hand over the reins," the report said. While the report said that Apple is unlikely to name a new CEO before its next earnings report in late January, it went on to ...
iOS 26

Everything New in iOS 26.2 Beta 3

Monday November 17, 2025 3:20 pm PST by
Apple provided developers with the third beta of an upcoming iOS 26.2 update, and there are still new features that are being added with each beta that we get. We've rounded up all of the changes that Apple made in beta 3. AirDrop Apple added new AirDrop functionality, providing a way for two people to share files temporarily without having to add one another as contacts. iOS 26.2...
AirPods Pro Firmware Feature

Apple Releases New Firmware for AirPods Pro 2, AirPods Pro 3, and AirPods 4

Thursday November 13, 2025 11:35 am PST by
Apple today released new firmware designed for the AirPods Pro 3, the AirPods 4, and the prior-generation AirPods Pro 2. The AirPods Pro 3 firmware is 8B25, while the AirPods Pro 2 and AirPods 4 firmware is 8B21, all up from the prior 8A358 firmware released in October. There's no word on what's include in the updated firmware, but the AirPods Pro 2, AirPods 4 with ANC, and AirPods Pro 3...
best early black friday deals

Best Black Friday Apple Deals Live Now - Save on AirPods, iPads, and Apple Watches

Saturday November 15, 2025 1:45 pm PST by
We're officially in the month of Black Friday, which will take place on Friday, November 28 in 2025. As always, this will be the best time of the year to shop for great deals, including popular Apple products like AirPods, iPad, Apple Watch, and more. In this article, the majority of the discounts will be found on Amazon. Note: MacRumors is an affiliate partner with some of these vendors. When ...
Apple Wallet ID Illinois

iPhone Driver's License Feature Launching in Illinois

Tuesday November 18, 2025 8:47 am PST by
In select U.S. states, residents can add their driver's license or state ID to the Wallet app on the iPhone and Apple Watch, providing a convenient and contactless way to display proof of identity or age at select airports and businesses, and in select apps. Starting this Wednesday, November 19, the feature will be available to residents of Illinois. The announcement confirmed that the...
iPhone Pocket Short

iPhone Pocket Now Available to Order, But Already Selling Out

Friday November 14, 2025 6:20 am PST by
Apple recently teamed up with Japanese fashion brand ISSEY MIYAKE to create the iPhone Pocket, a limited-edition knitted accessory designed to carry an iPhone. iPhone Pocket is available to order on Apple's online store starting today, in the United States, France, China, Italy, Japan, Singapore, South Korea, and the United Kingdom. However, it is already completely sold out in the United...
apple silicon mac lineup 2024 feature purple m5

Apple's 2026 Mac Plans

Friday November 14, 2025 3:23 pm PST by
Most of Apple's Macs are slated to get M5 chips across 2026, and there's a possibility we'll even see the first M6 chips toward the end of the year. Updates are planned for everything from the MacBook Air to the Mac Studio. MacBook Air (Early 2026) The MacBook Air will be one of the first Macs to get a 2026 refresh, with an update planned for the first few months of the year. The MacBook...
applecare apple care banner

Apple Brings New AppleCare+ Options to India

Tuesday November 18, 2025 8:42 am PST by
Apple today announced an expansion of AppleCare+ coverage in India, with new options for monthly and annual plans, and the addition of Theft and Loss for iPhone for the first time. Options for monthly and annual AppleCare+ plans in India provide more choice and flexibility, allowing users to keep coverage for as long as they require. Apple's vice president of Worldwide iPhone Product...
CarPlay Liquid Glass Dark

Here's When Tesla is Expected to Add Support for Apple CarPlay

Sunday November 16, 2025 6:49 am PST by
In his Power On newsletter today, Bloomberg's Mark Gurman reiterated that Tesla plans to add Apple CarPlay support to its vehicles "in the coming months." This is easily the biggest news for the regular version of CarPlay in years, should Tesla actually follow through with offering the system in its vehicles. As noted by Gurman, this would be a stunning reversal for Tesla and its CEO Elon ...
tvOS 26 Profiles

tvOS 26.2 Adds a Useful New Feature to Your Apple TV

Friday November 14, 2025 10:02 am PST by
Starting with the upcoming tvOS 26.2 update, currently in beta, additional profiles created on the Apple TV no longer require their own Apple Account. In the Settings app on the Apple TV, under Profiles and Accounts, anyone can create a new profile by simply entering a name and indicating whether the profile is for a kid. The profile will be associated with the primary user's Apple Account,...