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

Dynamic Island iPhone 18 Pro Feature

11 Reasons to Wait for the iPhone 18 Pro

Monday May 11, 2026 9:01 am PDT by
We're only four months out from the launch of Apple's premium next-generation smartphone lineup, and while we're not expecting a sea change in terms of functionality, there are still several enhancements rumored to be coming to the iPhone 18 Pro and iPhone 18 Pro Max. One thing worth noting is that Apple is reportedly planning a major change to its iPhone release cycle this year, adopting a...
iOS 26

iOS 26.5 Features: Everything New in iOS 26.5

Monday May 11, 2026 5:09 pm PDT by
Apple released iOS 26.5 after a few months of beta testing, and while it doesn't have the Siri features we were hoping for since those are being held until iOS 27, there are a handful of useful changes worth knowing about. Subscribe to the MacRumors YouTube channel for more videos. End-to-End Encryption for RCS Support for end-to-end encryption (E2EE) for RCS messages between iPhone and...
General Apps Reddit Feature

Reddit Starts Blocking Mobile Website, Pushing Users to App Instead

Monday May 11, 2026 6:10 am PDT by
Social network Reddit recently began blocking mobile visitors to its website while pushing them to download the official Reddit app, and it's fair to say that the move is not going down well with users. If you visit reddit.com on your iPhone today, you may see a new popup that can't be dismissed, asking you to "get the app to keep using Reddit." A Reddit spokesperson told Ars Technica...

Top Rated Comments

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

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

Stellar writing there. Well done MacRumors.
Score: 11 Votes (Like | Disagree)
Prodo123 Avatar
180 months ago
Hope this fixes the battery issue.
Score: 10 Votes (Like | Disagree)
thelink Avatar
180 months ago
Steve Jobs would never had allowed this. ;)
Score: 9 Votes (Like | Disagree)
Watabou Avatar
180 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
180 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)