Apple Seeds First Build of OS X 10.8.1 to Developers - MacRumors
Skip to Content

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

iPhone 18 Pro Deep Red Feature

iPhone 18 Pro Launching in Two Months With These 12 New Features

Friday July 17, 2026 10:39 am PDT by
It is now mid-July, and that means the iPhone 18 Pro and iPhone 18 Pro Max are now just two months away. The devices are expected to look similar to the iPhone 17 Pro and iPhone 17 Pro Max, but there will still be many year-over-year changes, with rumored features including a smaller Dynamic Island, 5G via satellite, and more. Apple is expected to unveil the iPhone 18 Pro, iPhone 18 Pro Max, ...
iCloud General Feature Redux

Apple Raises iCloud+ Prices in 8 Countries

Friday July 17, 2026 11:56 am PDT by
Apple has increased the price of iCloud+ in Nigeria, Türkiye, Vietnam, Japan, Egypt, New Zealand, the Philippines, and Indonesia, according to an updated version of its iCloud support document. Price increases range from 11 percent to 55 percent depending on the plan and the country. Nigeria saw the biggest hike, and a 50GB plan is now ₦1,300, up from ₦900. Türkiye saw the next largest...
iphone 17 cyber

Apple Closes Unlocked iPhone Loophole for T-Mobile and Verizon Financing

Wednesday July 15, 2026 3:20 pm PDT by
Carrier-financed iPhones purchased from Apple will soon be locked to the carrier, ending a workaround customers used to purchase an unlocked iPhone on a payment plan. Until the rule change, buying an iPhone from Apple and opting for financing through Verizon or T-Mobile meant you would get an iPhone not locked to either carrier's network. That's no longer the case, and now iPhones financed...

Top Rated Comments

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

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

Stellar writing there. Well done MacRumors.
Score: 11 Votes (Like | Disagree)
Prodo123 Avatar
182 months ago
Hope this fixes the battery issue.
Score: 10 Votes (Like | Disagree)
thelink Avatar
182 months ago
Steve Jobs would never had allowed this. ;)
Score: 9 Votes (Like | Disagree)
Watabou Avatar
182 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
182 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)