Editor's note: The projected rollout date for Yosemite has been updated in this story.
Apple yesterday released the third public beta of OS X Yosemite, shipping the preview a few days earlier than expected.
The update, labeled build "14A361p," accompanied the debut of the eighth developer preview, also on Monday. The latter was available only to registered developers, who pay $99 annually for access to pre-release software so that they can begin building new apps and modify existing ones for what Apple also calls OS X 10.10.
This week's eighth developer preview and third public beta are nearly identical in content and operation. The former was tagged as build "14A361c."
Last month, Computerworld forecast that Apple would release the third public beta on Thursday, Sept. 18, assuming that the last two builds exposed a pattern of issuing the public beta three days after every other developer preview.
The slight change of timing may mean little or nothing, or could signal that Apple plans on squeezing one more public beta into the process before it locks down the code for a "gold master," or GM, the final pre-release version that is, for all intents, the polished code which will be offered to all.
Bereft of an official ship date from Apple for Yosemite, the most likely would be Oct. 21, a date matching last year's schedule with OS X Mavericks.
An alternate explanation is that Apple wanted to refresh the Yosemite public beta before Wednesday's appearance of iOS 8. New features in OS X and iOS, called "Continuity," will allow customers who own both Macs and iPhones or iPads to hand off in-progress tasks, like a half-finished document or email, from one device to another. Other Continuity components include receipt of text messages on Macs, taking and receiving phone calls from the Mac, and an instant ad hoc Wi-Fi hotspot triggered when an iPhone is near a connection-less Mac.
The text message handoff will not be implemented in iOS 8 off the bat; Apple has said that an update to the mobile operating system will add the functionality in October.
This summer's Yosemite public beta was the first for an Apple operating system since 2000, when the company charged customers $29.95 for the privilege of running an early version of what later became OS X 10.0, better known as Cheetah.
The public beta can be installed only on Macs running OS X Mavericks. Those machines can include iMacs from the mid-2007 model on; 13-in. MacBooks from late 2008 (aluminum case) or early 2009 (plastic case) forward; MacBook Pros from mid- and late-2007 and on; MacBook Airs from late 2008 and later; Mac Minis from early 2009 and after; and Mac Pros from early 2008 and later.
Most Macs will be able to upgrade immediately upon Yosemite's launch: According to analytics vendor Net Applications, approximately 67% of all Macs will be running Mavericks by the end of this month.
Participants in the public beta will be able to install the final edition in place of the preview when the former ships next month. Yosemite, like its predecessor Mavericks, will be free to download from the Mac App Store when it finalizes.
The third Yosemite public beta can be retrieved by those already running the preview from the Mac App Store by selecting "Software Update..." from the Apple menu on the top-of-the-screen menu bar.