mountainlionApple today seeded build 12F33 of OS X 10.8.5 to developers, marking the eighth beta iteration of 10.8.5. The release comes exactly one week after the previous OS X 10.8.5 beta, build 12F30.

As with previous betas, the update contains no known issues and can be downloaded via Apple’s Developer page or through the software update tool of the Mac App Store.

Apple’s OS X 10.8.5 beta is being tested alongside the next version of the operating system, OS X Mavericks. Apple has thus far seeded five developer previews of Mavericks and plans to offer the new operating system to the public in the fall.

Top Rated Comments

M5RahuL Avatar
160 months ago
What are you finding so dramatically better?
- Scrolling on HD4000 is far superior, given the allocated memory has been increased to 1024 MB. My point of reference is the verge, and resizing the App Store.

- Battery life is a bit [ ~ 1 hr ] better. YMMV on this.

- Inclusion of iBooks [ in the latest build OS X 10.9 (13A538g) aka DP 5 ]

- Shut down issue is *somewhat* fixed. Shut down is now faster than on 10.8.x

- Tabs in Finder is much better than opening multiple Finder windows.

That's all I can recall right off...
Score: 5 Votes (Like | Disagree)
dastinger Avatar
160 months ago
Why post it on a Mountain Lion update related thread? :confused:
Score: 4 Votes (Like | Disagree)
macs4nw Avatar
160 months ago
Although I'm glad APPLE is taking their time to uncover hidden bugs as much as possible before the GMs of iOS7, Mavericks and ML10.8.5, these bi-weekly dev releases make these next 5-6 weeks seem to last even longer.....arrgh
Score: 1 Votes (Like | Disagree)

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