Apple runs two betas simultaneously of iOS and OS X
On Monday, Apple seeded developers with the first betas of iOS 9.3 and OS X 10.11.4, then followed up on Thursday by releasing the same builds to the testers who had previously registered with the company's public preview program.
Handing out previews to developers and the public is nothing new for Apple: It's offered betas of upcoming updates and upgrades to developers for ages, and to non-developers since mid-2014, when it debuted a public preview for OS X 10.9, aka Mavericks.
What was noteworthy this week was that Apple had already issued betas of versions preceding iOS 9.3. and OS X 10.11.4 to both developers and the general public. In other words, Apple is testing two versions of each operating system simultaneously, a first.
Apple released the second beta of iOS 9.2.1 -- the immediate successor to Dec. 8's iOS 9.2 -- on Jan. 4, and the second preview of OS X 10.11.3 on Jan. 6. As of mid-day Friday, Apple had not released the final code for either iOS 9.2.1 or OS X 10.11.3.
It's unclear whether the move presaged a faster development-and-release tempo by Apple or was more about promoting the newer of the two versions, especially iOS 9.3, which the Cupertino, Calif. company has touted more aggressively than typical "point updates," or those that increment the number after the decimal point. For instance, Apple this week launched a dedicated page on its website to trumpet the changes in iOS 9.3, something it normally does only for upcoming upgrades, like that from iOS 8 to iOS 9, and OS X Yosemite to OS X El Capitan, last summer.
Apple will certainly release iOS 9.2.1 and OS X 10.11.3 before their followers, but the arrival of iOS 9.3 and OS X 10.11.4 may also indicate final code for the predecessors is imminent.
iOS and OS X owners interested in running previews can register with the beta program here, then enroll their devices in one or both programs. Developers can download the preliminary releases from the Apple website.