Apple Releases First Developer Preview of OS X Mountain Lion, Public Launch in Late Summer - MacRumorsOpen MenuShow RoundupsShow Forums menuVisit ForumsOpen Sidebar
Skip to Content

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

American Express Gold Apple Pay Feature

American Express Announces New Apple Pay Feature

Tuesday June 30, 2026 10:27 am PDT by
American Express today announced that you can now redeem Membership Rewards points when checking out with Apple Pay on the web and in apps on the iPhone and iPad. When checking out with Apple Pay on iOS 18 or iPadOS 18 or later, tap on your eligible American Express card (Platinum, Gold, Green, and others) and select the Membership Rewards points option. You can use points to cover all or...
Apple Acquires Award Winning App Play Feature

Apple Acquires Award-Winning App 'Play'

Monday June 29, 2026 7:39 am PDT by
In February, Apple notified the European Commission that it would be acquiring certain assets from and have the right to hire certain employees from Rabbit 3 Times, the company behind the award-winning app design tool Play. The notification was published on the European Commission's website this week, following a four-month waiting period. Play was a Mac and iPhone app that allowed designers ...
series 10 apple watch titanium digital crown

Report: Apple Watch Redesign Coming Next Year With New Band System

Tuesday June 30, 2026 8:45 am PDT by
A "major overhaul" of the Apple Watch's design is due to arrive next year with a new system for connecting bands, according to a known Weibo leaker. In a set of recent posts, the leaker known as "Instant Digital" linked the new claim to older rumors about an "Apple Watch X" model, which was said to introduce a fresh design and break compatibility with the existing watch band system. Citing...

Top Rated Comments

igazza Avatar
188 months ago
I didn't expect that
Score: 75 Votes (Like | Disagree)
Patrick J Avatar
188 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
188 months ago
I thought it was April Fools Day for a second... nice surprise.
Score: 43 Votes (Like | Disagree)
Agent OrangeZ Avatar
188 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
188 months ago
Did not see this one coming.

apple releases first developer preview of os x mountain lion public launch in late summer image
Score: 29 Votes (Like | Disagree)
rdowns Avatar
188 months ago
Anyone guess what default setting for Gatekeeper will be, hmm could it be the App store only ???


apple releases first developer preview of os x mountain lion public launch in late summer image

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)

🔗 Related Apple News & Rumors

Stay updated with the latest Apple ecosystem news and verified rumors