Apple Seeds Golden Master of OS X Mountain Lion to Developers - MacRumorsOpen MenuShow RoundupsShow Forums menuVisit ForumsOpen Sidebar
Skip to Content

Apple Seeds Golden Master of OS X Mountain Lion to Developers

200newfeatures
"200 New Features" Mountain Lion slide shown at WWDC

Apple released the Golden Master (GM) version of OS X Mountain Lion to developers today. The "golden master" designation indicates that this version of the software is intended to be the final version released to the public, barring any last-minute issues. The Build is 12A269.

Apple first previewed Mountain Lion in February, highlighting many features already present in iOS, including Messages, Reminders, Notes, Notification Center, Game Center and more at that time. At WWDC, Apple announced additional features, including Dictation, iCloud Tabs, and 'Power Nap'.

We previously highlighted this video which shows off many of the new features found in Mountain Lion:


Mountain Lion will be priced at $19.99 and released to the Mac App Store in July.

Popular Stories

iPhone Duo Display Cracking

Apple Alerts Stores to iPhone Duo's Display Cracking Issue

Friday October 30, 2026 3:20 pm PDT by
In a memo shared with Apple Stores and Apple Authorized Service Providers this week, and later obtained by MacRumors, Apple provided technicians with guidance on how to diagnose and address the iPhone Duo's inner display cracking issue. If a customer reports the issue, Apple advised technicians to inspect the iPhone Duo and repair or replace it in accordance with their standard procedures....
iPad mini OLED feature 1

Apple Executive Comments on New iPad Mini Lacking 120Hz Display

Thursday October 29, 2026 1:47 pm PDT by
While the new iPad mini has an OLED display, the device does not support ProMotion, meaning the display's refresh rate is limited to 60Hz instead of 120Hz. ProMotion support would have allowed for the iPad mini's refresh rate to automatically adjust from 10Hz to 120Hz depending on the content being displayed, but evidently Apple has kept the feature exclusive to the iPad Pro among iPad...
Pinched iPad Mini

Apple Avoids Showing Pinched Fingers on iPad Mini Page in South Korea

Thursday October 29, 2026 11:52 am PDT by
In the U.S. and most other countries, Apple's website shows the new iPad mini being held by pinched fingers, but this is not the case in South Korea. The new iPad mini shown with pinched fingers on Apple's website in the U.S. On its South Korean website, Apple simply shows an image of the iPad mini on its own. The new iPad mini shown without pinched fingers on Apple's website in South Korea ...

Top Rated Comments

heisenberg123 Avatar
187 months ago
Can anyone give me a download link please?

not sure whats worse
a) not knowing how to obtain things illegally on net in 2012
b) asking for help to do it on a forum thats so against it
Score: 72 Votes (Like | Disagree)
Tonewheel Avatar
187 months ago
[SIZE="4"]I'm honestly not that excited about this upgrade. Nothing exciting has really come out since Tiger or Leopard in my opinion. Most of these new features will be used for like 5 minutes by the mainstream user because they're just not that important (i.e. Reminders). And they also end up taking up more precious RAM & most importantly, battery life (on a laptop). Can someone name something that is really that ground breaking in this release? It just seems like things were reorganized & tweaked a bit.

P.S.
I've been in the Apple game since 1985, so I know a good Apple product when I see it. I'm not saying this is bad, but it's just not that amazing. Maybe OS 11 will be exciting?
[/SIZE]

Please type larger next time.
Score: 61 Votes (Like | Disagree)
thelink Avatar
187 months ago
Can anyone give me a download link please?

https://developer.apple.com/ (https://developer.apple.com/)
That's a good place to start. Have fun. :)
Score: 26 Votes (Like | Disagree)
187 months ago
Bye bye Lion

Seems like we hardly got to know each other :o
Score: 24 Votes (Like | Disagree)
187 months ago
Hooray…..

Just released, 10.8 GM build.

Downloading as I type….
Score: 22 Votes (Like | Disagree)
ScottishDuck Avatar
187 months ago
A reminder on how to make your own USB copy. Requires a 8GB+ USB drive

*Download the installer from the app store.

*Right-click installer -> "Show Package Contents"

apple seeds golden master of os x mountain lion to developers image

*Contents -> Shared Support -> InstallESD.dmg (open it/mount it)

apple seeds golden master of os x mountain lion to developers image

*Open the terminal and copy this command:

open /Volumes/Mac\ OS\ X\ Install\ ESD/BaseSystem.dmg
apple seeds golden master of os x mountain lion to developers image

*Now open Diskutility and "restore" BaseSystem.dmg to your USB drive.

***PLEASE NOTE THIS REQUIRES YOUR USB HAS A GUID PARTITION TABLE***

[Changing partition table to GUID]
apple seeds golden master of os x mountain lion to developers image

apple seeds golden master of os x mountain lion to developers image

[Restoring the DMG]
apple seeds golden master of os x mountain lion to developers image

*Now open your newly restored USB drive

apple seeds golden master of os x mountain lion to developers image

*System -> Installation

apple seeds golden master of os x mountain lion to developers image

*Delete the link called "Packages" and then create a new folder with the same name

apple seeds golden master of os x mountain lion to developers image

apple seeds golden master of os x mountain lion to developers image

*Open the terminal again and copy this to it:

open /Volumes/Mac\ OS\ X\ Install\ ESD/Packages
apple seeds golden master of os x mountain lion to developers image

*Copy everything in this folder to the "Packages" folder you created on your USB.

apple seeds golden master of os x mountain lion to developers image

apple seeds golden master of os x mountain lion to developers image

**Note this stage might take a while**

apple seeds golden master of os x mountain lion to developers image

Hurray you now have a working installer.

----------------------------------------------------------------------------------------

A note:

This guide may seem different to others you have seen but it works better:

*The standard installer will copy the installation DMG to your hard drive and then re-run the installation using that. i.e you are needlessly running the install twice. My way doesn't do that.

*This installer allows you to clean install
Score: 20 Votes (Like | Disagree)
Latest Stories
Apple Watch Ultra 4 Hits All-Time Low Price With Amazon's $99 Discount
Apple Watch Ultra 4 Hits All-Time Low Price With Amazon's $99 Discount
18 hours ago
Reminder: Apple's Big Discount on Beats 360 Ear Cushions Ends Today
Reminder: Apple's Big Discount on Beats 360 Ear Cushions Ends Today
18 hours ago
Here's a New Tour of Apple's HomeView Software
Here's a New Tour of Apple's HomeView Software
18 hours ago
Apple Reveals New iPad Mini's Battery Capacity
Apple Reveals New iPad Mini's Battery Capacity
19 hours ago
Top Stories: Apple's Big MacBook Pro, iPad mini and iMac Updates
Top Stories: Apple's Big MacBook Pro, iPad mini and iMac Updates
21 hours ago
'Pluribus' Season 2 Reportedly Starts Production Today
'Pluribus' Season 2 Reportedly Starts Production Today
1 day ago
iPhone 18 Pro Sales Surge in China, Offsetting Decline in U.S. and Japan
iPhone 18 Pro Sales Surge in China, Offsetting Decline in U.S. and Japan
1 day ago
HomeView Software 27.2: Wallpapers, Control Center, and More
HomeView Software 27.2: Wallpapers, Control Center, and More
1 day ago
Apple Alerts Stores to iPhone Duo's Display Cracking Issue
Apple Alerts Stores to iPhone Duo's Display Cracking Issue
1 day ago
iOS 27.3 Will Enable These Apple Intelligence Features in China
iOS 27.3 Will Enable These Apple Intelligence Features in China
2 days ago
Apple Says iOS 27.3 Beta Coming Next Week
Apple Says iOS 27.3 Beta Coming Next Week
2 days ago
Apple's Flash Storage Suppliers Are Finally 'Getting Their Revenge'
Apple's Flash Storage Suppliers Are Finally 'Getting Their Revenge'
2 days ago
14 New Things Your iPhone Can Do in iOS 27.2
14 New Things Your iPhone Can Do in iOS 27.2
2 days ago
iPhone Duo Review: One Week Later
iPhone Duo Review: One Week Later
2 days ago
Samsung Mocks iPhone Duo Display Cracks in New Ad Campaign
Samsung Mocks iPhone Duo Display Cracks in New Ad Campaign
2 days ago
The MacRumors Show: OLED MacBook Pro, iPad Mini 8, and More
The MacRumors Show: OLED MacBook Pro, iPad Mini 8, and More
2 days ago
MacBook Pro With Touch Display: 15 More Details Revealed
MacBook Pro With Touch Display: 15 More Details Revealed
2 days ago
Russia Places Apple on State Surveillance Registry
Russia Places Apple on State Surveillance Registry
2 days ago
Halloween Weekend Brings Discounts on Apple Accessories and Pre-Orders
Halloween Weekend Brings Discounts on Apple Accessories and Pre-Orders
2 days ago
Apple Has Released More Than 25 New Products in the Past Two Months
Apple Has Released More Than 25 New Products in the Past Two Months
2 days ago
Local Code Launches as Free, Private AI Assistant Tool for Mac
Local Code Launches as Free, Private AI Assistant Tool for Mac
2 days ago
Apple Acquires Ascend.io
Apple Acquires Ascend.io
2 days ago
HomePod Mini 2 Launches Today: All the New Features
HomePod Mini 2 Launches Today: All the New Features
2 days ago
AirTag 2 4-Pack Drops to New Low Price of $69.99
AirTag 2 4-Pack Drops to New Low Price of $69.99
2 days ago
Rian Johnson's iPhone Camera App Goes Viral
Rian Johnson's iPhone Camera App Goes Viral
2 days ago
Where Did All the iPhone Duos Go? Mostly to Apple's Stores
Where Did All the iPhone Duos Go? Mostly to Apple's Stores
2 days ago
Apple's Touchscreen MacBook Pro Could Ship 1.5M Units in 2027
Apple's Touchscreen MacBook Pro Could Ship 1.5M Units in 2027
2 days ago
New Apple TV 4K and iPad Mini: RAM Amounts Revealed
New Apple TV 4K and iPad Mini: RAM Amounts Revealed
2 days ago
Apple Executive Comments on New iPad Mini Lacking 120Hz Display
Apple Executive Comments on New iPad Mini Lacking 120Hz Display
3 days ago
Here's a Hands-On Look at HomePod Mini 2's New Two-Tone Colors
Here's a Hands-On Look at HomePod Mini 2's New Two-Tone Colors
3 days ago

🔗 Related Apple News & Rumors

Stay updated with the latest Apple ecosystem news and verified rumors