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 17 Pro Iridescent Feature 2

iPhone 17 Pro Clear Case Leak Reveals Three Key Changes

Sunday August 31, 2025 1:26 pm PDT by
Apple is expected to unveil the iPhone 17 series on Tuesday, September 9, and last-minute rumors about the devices continue to surface. The latest info comes from a leaker known as Majin Bu, who has shared alleged images of Apple's Clear Case for the iPhone 17 Pro and Pro Max, or at least replicas. Image Credit: @MajinBuOfficial The images show three alleged changes compared to Apple's iP...
iPhone 17 Pro Dark Blue and Orange

iPhone 17 Release Date, Pre-Orders, and What to Expect

Thursday August 28, 2025 4:08 am PDT by
An iPhone 17 announcement is a dead cert for September 2025 – Apple has already sent out invites for an "Awe dropping" event on Tuesday, September 9 at the Apple Park campus in Cupertino, California. The timing follows Apple's trend of introducing new iPhone models annually in the fall. At the event, Apple is expected to unveil its new-generation iPhone 17, an all-new ultra-thin iPhone 17...
iphone 16 pro ghost hand

iPhone 17 Pro: 5 Reasons Not to Upgrade This Year

Monday September 1, 2025 4:35 am PDT by
Apple will launch its new iPhone 17 series this month, and the iPhone 17 Pro models are expected to get a new design for the rear casing and the camera area. But more significant changes to the lineup are not expected until next year, when the iPhone 18 models arrive. If you're thinking of trading in your iPhone for this year's latest, consider the following features rumored to be coming to...
iPhone 17 Pro 3 4ths Perspective Aluminum Camera Module 1

New iPhone 17 Pro Details: Brighter Display, Best Battery Life, and More

Wednesday September 3, 2025 5:33 am PDT by
Apple's iPhone 17 Pro and iPhone 17 Pro Max models will feature a number of significant display, thermal, and battery improvements, according to new late-stage rumors. According to the Weibo leaker known as "Instant Digital," the iPhone 17 Pro models will feature displays with higher brightness, making it more suitable for use in direct sunlight for prolonged periods. The iPhone 16 Pro and...
iPhone 17 Pro Iridescent Feature 2

iPhone 17 and iPhone 17 Pro Prices Estimated Ahead of Apple Event Next Week

Tuesday September 2, 2025 1:50 pm PDT by
Just one week before Apple is expected to unveil the iPhone 17 series, an analyst has shared new price estimates for the devices. Here are J.P. Morgan analyst Samik Chatterjee's price estimates for the iPhone 17 series in the United States, according to 9to5Mac: Model Starting Price Model Starting Price Change iPhone 16 $799 iPhone 17 ...
xiaomi apple ad india

Apple and Samsung Push Back Against Xiaomi's Bold India Ads

Friday August 29, 2025 4:54 am PDT by
Apple and Samsung have reportedly issued cease-and-desist notices to Xiaomi in India for an ad campaign that directly compares the rivals' devices to Xiaomi's products. The two companies have threatened the Chinese vendor with legal action, calling the ads "disparaging." Ads have appeared in local print media and on social media that take pot shots at the competitors' premium offerings. One...
iOS 18 on iPhone Arrow Down

Apple Preparing iOS 18.7 for iPhones as iOS 26 Release Date Nears

Sunday August 31, 2025 4:35 pm PDT by
Apple is preparing to release iOS 18.7 for compatible iPhone models, according to evidence of the update in the MacRumors visitor logs. We expect iOS 18.7 to be released in September, alongside iOS 26. The update will likely include fixes for security vulnerabilities, but little else. iOS 18.7 will be one of the final updates ever released for the iPhone XS, iPhone XS Max, and iPhone XR,...

Top Rated Comments

heisenberg123 Avatar
172 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
172 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
172 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)
cadillac1234 Avatar
172 months ago
Bye bye Lion

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

Just released, 10.8 GM build.

Downloading as I type….
Score: 22 Votes (Like | Disagree)
ScottishDuck Avatar
172 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"

MacRumors content image

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

MacRumors content image

*Open the terminal and copy this command:

open /Volumes/Mac\ OS\ X\ Install\ ESD/BaseSystem.dmg
MacRumors content 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]
MacRumors content image

MacRumors content image

[Restoring the DMG]
MacRumors content image

*Now open your newly restored USB drive

MacRumors content image

*System -> Installation

MacRumors content image

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

MacRumors content image

MacRumors content image

*Open the terminal again and copy this to it:

open /Volumes/Mac\ OS\ X\ Install\ ESD/Packages
MacRumors content image

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

MacRumors content image

MacRumors content image

**Note this stage might take a while**

MacRumors content 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)