Apple Releases First Developer Preview of OS X Mountain Lion, Public Launch in Late Summer

os x mountain lion sneak peek iconApple today announced that it has released the first developer preview of the company's next-generation operating system, named OS X Mountain Lion. The release will bring over 100 new features, including a number of those familiar to iOS users such as Messages, Notes, Reminders, Game Center, Notification Center, Twitter integration, and AirPlay Mirroring. The first developer preview is available to registered developers today, with a public launch through the Mac App Store scheduled for late this summer.

“The Mac is on a roll, growing faster than the PC for 23 straight quarters, and with Mountain Lion things get even better,” said Philip Schiller, Apple’s senior vice president of Worldwide Marketing. “The developer preview of Mountain Lion comes just seven months after the incredibly successful release of Lion and sets a rapid pace of development for the world’s most advanced personal computer operating system.”

OS X Mountain Lion included deeper integration with iCloud to automatically configure services like Mail, FaceTime, and Find My Mac, while iCloud Documents handles automatic push syncing of documents across devices. Security is also a focus in the upcoming release, with a new feature called Gatekeeper helping users to specify from which sources apps may be installed on their computers.

os x mountain lion macs
Finally, Apple is continuing its emphasis on expanding into China with substantial improvements for Chinese users included enhanced Chinese input methods and the addition of Baidu as a search engine option. Integration with Chinese email and video hosting sites as well as the Sina weibo microblogging service is also included.

Advance previews of OS X Mountain Lion are available from a number of sources:

- The Loop
- Macworld
- Engadget
- The Verge
- AllThingsD
- CNET
- The Wall Street Journal's interview with Tim Cook

And perhaps most interestingly, Daring Fireball's John Gruber relates the private briefing he received from Phil Schiller and other Apple executives.

Popular Stories

Apple Logo Top Half

Early iOS 26 Software Leak Uncovers Dozens of Upcoming Apple Features

Monday December 15, 2025 3:05 pm PST by
Software from an iPhone prototype running an early build of iOS 26 leaked last week, giving us a glimpse at future Apple devices and iOS features. We recapped device codenames in our prior article, and now we have a list of some of the most notable feature flags that were found in the software code. In some cases, it's obvious what the feature flags are referring to, while some are more...
apple beta 26 lineup

Apple Leak Confirms Work on Foldable iPhone, AirTag 2, and Dozens More Devices

Monday December 15, 2025 2:05 pm PST by
Last week, details about unreleased Apple devices and future iOS features were shared by Macworld. This week, we learned where the information came from, plus we have more findings from the leak. As it turns out, an Apple prototype device running an early build of iOS 26 was sold, and the person who bought it shared the software. The OS has a version number of 23A5234w, and the first...
iOS 26

iOS 26.3 Beta 1 Features: What's New So Far

Monday December 15, 2025 4:23 pm PST by
Apple is testing iOS 26.3, the next version of iOS 26 that will launch around January. Since iOS 26.3's testing is happening over the holidays, it is a smaller update with fewer features than we've seen in prior betas. We've rounded up what's new so far, and we'll add to our list with subsequent betas if we come across any other features. Transfer to Android Apple is making it simpler...
iOS 26

iOS 26.4 and iOS 27 Features Revealed in New Leak

Friday December 12, 2025 10:56 am PST by
Macworld's Filipe Espósito today revealed a handful of features that Apple is allegedly planning for iOS 26.4, iOS 27, and even iOS 28. The report said the features are referenced within the code for a leaked internal build of iOS 26 that is not meant to be seen by the public. However, it appears that Espósito and/or his sources managed to gain access to it, providing us with a sneak peek...
Apple Foldable Thumb

Leak Reveals Foldable iPhone Details

Monday December 15, 2025 9:09 am PST by
The first foldable iPhone will feature a series of design and hardware firsts for Apple, according to details shared by the Weibo leaker known as Digital Chat Station. According to a new post, via machine translation, Apple is developing what the leaker describes as a "wide foldable" device, a term used to refer to a horizontally oriented, book-style foldable with a large internal display....
iPhone Top Left Hole Punch Face ID Feature Purple

iPhone 18 Pro Features Leaked in New Report, Including Under-Screen Face ID

Tuesday December 16, 2025 8:44 am PST by
Next year's iPhone 18 Pro and iPhone 18 Pro Max will be equipped with under-screen Face ID, and the front camera will be moved to the top-left corner of the screen, according to a new report from The Information's Wayne Ma and Qianer Liu. As a result of these changes, the report said the iPhone 18 Pro models will not have a pill-shaped Dynamic Island cutout at the top of the screen....
airpods max 2024 colors

AirPods Max 2 Likely to Offer These 10 New Features

Monday December 15, 2025 7:41 am PST by
Apple released the AirPods Max on December 15, 2020, meaning the over-ear headphones launched five years ago today. While the AirPods Max were updated with a USB-C port and new color options last year, followed by support for lossless audio and ultra-low latency audio this year, the headphones lack some of the features that have been introduced for newer generations of the regular AirPods and the ...
apple iphone air battery pack

Apple Aims to Boost Popularity of iPhone Air 2 in Two Ways

Tuesday December 16, 2025 11:06 am PST by
We have been covering iPhone 18 Pro, iPhone 17e, and iPhone Fold details from The Information's report about future iPhone models, and next up is the iPhone Air 2. The report says that Apple aims to make the iPhone Air 2 more attractive in two ways. First, Apple is apparently considering adding a second rear camera to the device, which would resolve a key limitation. The current iPhone...

Top Rated Comments

igazza Avatar
181 months ago
I didn't expect that
Score: 75 Votes (Like | Disagree)
Patrick J Avatar
181 months ago
I love the fact that this came out of the blue, and it really seems to be a polish to Lion. Apple is moving in the right direction.
Score: 50 Votes (Like | Disagree)
Mac21ND Avatar
181 months ago
I thought it was April Fools Day for a second... nice surprise.
Score: 43 Votes (Like | Disagree)
Agent OrangeZ Avatar
181 months ago
Hmmm....

OSX 10.1 is known as "Puma."

OSX 10.8 will be known as "Mountain Lion."

According to Wikipedia:
"The cougar (Puma concolor), also known as puma, mountain lion, mountain cat, catamount or panther, depending on the region, is a mammal of the family Felidae, native to the Americas. This large, solitary cat has the greatest range of any large wild terrestrial mammal in the Western Hemisphere,[3] extending from Yukon in Canada to the southern Andes of South America. An adaptable, generalist species, the cougar is found in every major American habitat type. It is the second heaviest cat in the Western Hemisphere, after the jaguar. Although large, the cougar is most closely related to smaller felines and is closer genetically to the domestic cat than to true lions."
Score: 36 Votes (Like | Disagree)
pewra Avatar
181 months ago
Did not see this one coming.

Score: 29 Votes (Like | Disagree)
rdowns Avatar
181 months ago
Anyone guess what default setting for Gatekeeper will be, hmm could it be the App store only ???




Gruber's take:

My favorite Mountain Lion feature, though, is one that hardly even has a visible interface. Apple is calling it “Gatekeeper”. It’s a system whereby developers can sign up for free-of-charge Apple developer IDs which they can then use to cryptographically sign their applications. If an app is found to be malware, Apple can revoke that developer’s certificate, rendering the app (along with any others from the same developer) inert on any Mac where it’s been installed. In effect, it offers all the security benefits of the App Store, except for the process of approving apps by Apple. Users have three choices which type of apps can run on Mountain Lion:

Only those from the App Store
Only those from the App Store or which are signed by a developer ID
Any app, whether signed or unsigned
The default for this setting is, I say, exactly right: the one in the middle, disallowing only unsigned apps. This default setting benefits users by increasing practical security, and also benefits developers, preserving the freedom to ship whatever software they want for the Mac, with no approval process.

Call me nuts, but that’s one feature I hope will someday go in the other direction — from OS X to iOS.
Score: 23 Votes (Like | Disagree)