Apple Seeds First Build of OS X 10.8.1 to Developers

Following on the heels of our report from Wednesday about Apple's preparations for developer seeds of OS X 10.8.1, Apple has now released the first build of the Mountain Lion update to developers, according to 9to5Mac.

The release has a build number of 12B13 and Apple reports no known issues, but asks developers to focus on a wide variety of areas for their testing. The delta update -- where only items that have changed are downloaded -- weighs in at 36.4MB.

NewImage
According to 9to5Mac, developers have been asked to test Active Directory, Microsoft Exchange in Mail, PAC proxies in Safari, SMB, USB, and Wi-Fi and audio when connected to the Apple Thunderbolt display.

The OS X 10.8.1 seed is available for download via the OS X Developer portal at developer.apple.com.

Popular Stories

apple store down feature

Here's Why the Apple Store is Going Down

Thursday November 27, 2025 1:01 pm PST by
Apple's online store is going down for a few hours on a rolling country-by-country basis right now, but do not get your hopes up for new products. Apple takes its online store down for a few hours ahead of Black Friday every year to tease/prepare for its annual gift card offer with the purchase of select products. The store already went down and came back online in Australia and New Zealand, ...
iPhone Pocket Short

iPhone Pocket is Now Completely Sold Out Worldwide

Tuesday November 25, 2025 7:16 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. However, it is now completely sold out in all countries where it was released. iPhone Pocket became available to order on Apple's online store starting Friday, November 14, in the United States, France, China, Italy, Japan, Singapore, ...
New Intel Logo

Apple and Intel Rumored to Partner on Mac Chips Again in a New Way

Friday November 28, 2025 7:33 am PST by
While all Macs are now powered by Apple's custom-designed chips, a new rumor claims that Apple may rekindle its partnership with Intel, albeit in a new and limited way. Apple supply chain analyst Ming-Chi Kuo today said Intel is expected to begin shipping Apple's lowest-end M-series chip as early as mid-2027. Kuo said Apple plans to utilize Intel's 18A process, which is the "earliest...
streaming black friday 2025

Best Black Friday Streaming Deals - Save Big on Apple TV, Disney+, Hulu, and More

Thursday November 27, 2025 1:14 pm PST by
We've been focusing on deals on physical products over the past few weeks, but Black Friday is also a great time of year to purchase a streaming membership. Some of the biggest services have great discounts for new and select returning members this week, including Apple TV, Disney+, Hulu, Paramount+, Peacock, and more. Note: MacRumors is an affiliate partner with some of these vendors. When...
iphone air camera

iPhone Air Flop Sparks Industry Retreat From Ultra-Thin Phones

Thursday November 27, 2025 3:14 am PST by
Apple's disappointing iPhone Air sales are causing major Chinese mobile vendors to scrap or freeze their own ultra-thin phone projects, according to reports coming out of Asia. Since the ‌iPhone Air‌ launched in September, there have been reports of poor sales and manufacturing cuts, while Apple's supply chain has scaled back shipments and production. Apple supplier Foxconn has...
iphone black friday gold

The Best Black Friday iPhone Deals Still Available

Friday November 28, 2025 6:24 am PST by
Cellular carriers have always offered big savings on the newest iPhone models during the holidays, and Black Friday 2025 sales have kicked off at AT&T, Verizon, T-Mobile, and more. Right now we're tracking notable offers on the iPhone 17, iPhone 17 Pro, iPhone 17 Pro Max, and iPhone Air. For even more savings, keep an eye on older models during the holiday shopping season. Note: MacRumors is...
Apple Foldable Thumb

Foldable iPhone to Debut These Three Breakthrough Features

Tuesday November 25, 2025 7:09 am PST by
Apple's first foldable iPhone is expected to launch alongside the iPhone 18 Pro models in fall 2026, and it's shaping up to include three standout features that could set it apart from the competition. The book-style foldable will reportedly feature an industry-first 24-megapixel under-display camera built into the inner display, according to a recent JP Morgan equity research report. That...

Top Rated Comments

sniffies Avatar
174 months ago
Hope this release fixes the bug where folder item count wouldn't update no matter what.

Score: 36 Votes (Like | Disagree)
tekno Avatar
174 months ago
"Apple seeds first seed..."

Stellar writing there. Well done MacRumors.
Score: 11 Votes (Like | Disagree)
Prodo123 Avatar
174 months ago
Hope this fixes the battery issue.
Score: 10 Votes (Like | Disagree)
thelink Avatar
174 months ago
Steve Jobs would never had allowed this. ;)
Score: 9 Votes (Like | Disagree)
Watabou Avatar
174 months ago
Rather small update....
It's actually a fairly big update. Code files are typically only a couple of kilobytes in size. So a 36.4MB update is fairly big. And anyways, Apple probably wants to just focus on the most critical updates first and then move on to the graphical bugs. Plus, this is only the first build.
Score: 6 Votes (Like | Disagree)
cjmillsnun Avatar
174 months ago
In other words, the biggest train wreck in OS X's history continues to be a train wreck with 10.8.1...other than the battery, nothing else is fixed or what?

Considering you've never bought ML and used it on your own mac. I don't think you're in a position to call it "The biggest train wreck in OS X's history". I've been using it since DP1 on my own Macs and it has held up fairly well.

There were far worse bugs in 10.6 when that came out but at the time you were saying "Microsoft is dead".

On the whole, the bugs in ML are relatively minor for a .0 release, and some of them are being fixed in this .1 release. This .1 developer release is the first seed. So again there may be more in the way of bug fixes to come in the next seed.

Your post is quite frankly ridiculous.
Score: 5 Votes (Like | Disagree)