Apple Seeds First Developer Build of Mac OS X 10.6.6 - MacRumorsOpen MenuShow RoundupsShow Forums menuVisit ForumsOpen Sidebar
Skip to Content

Apple Seeds First Developer Build of Mac OS X 10.6.6

225930 10 6 6 10j521 500

In a rather unusual move, Apple today seeded the first developer version of Mac OS X 10.6.6, known as Build 10J521, even before the company has publicly released Mac OS X 10.6.5.

As 9 to 5 Mac notes, there are no documented known issues in the build and the seed notes mention a focus on support for the forthcoming Mac App Store.

- Contains developer support for fetching and renewing App Store receipts. See "Validating App Store Receipts" for more details.

Interestingly, the Mac OS X 10.6.6 update is only 3.7 MB in size, suggesting only very minor tweaks at this point.

The unusual early seeding of Mac OS X 10.6.6 relative to its predecessor and the apparent requirement of Mac OS X 10.6.6 for certain Mac App Store functions suggest that Apple is likely fast-tracking the operating system update for release in the not-so-distant future.

Apple announced during its October 20th media event that the Mac App Store would launch on Mac OS X Snow Leopard within 90 days, and just yesterday the company began accepting submissions from developers for inclusion in the Mac App Store.

Popular Stories

iCloud iPhone 17 Pro

iPhone Users Who Pay for iCloud Storage Get Two New Perks on iOS 27

Thursday July 2, 2026 6:10 am PDT by
If you pay for certain iCloud+ storage plans beyond the 5GB that Apple offers for free, you will receive two more perks on iOS 27 at no additional cost. A summary of the two new iCloud+ perks on iOS 27:Increased daily usage limits for some new Apple Intelligence features, including image generation in the revamped Image Playground app. HomeKit Secure Video cameras receive generated video...
iPhone 4 on Black Feature

Apple Facing One of Its Worst Leaks Since the iPhone 4

Thursday July 2, 2026 9:53 am PDT by
Apple supplier Tata Electronics recently suffered a cyberattack that resulted in thousands of confidential files being published on the dark web, and this reportedly included some photos and documents related to the upcoming iPhone 18 Pro. We have elected not to share any of the leaked photos in this story due to the illegal nature in which they were obtained, but they can easily be found...
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...