Building a slide deck, pitch, or presentation? Here are the big takeaways:

  • Starting on April 12, users will be given one notification per affected 32-bit app that the developer needs to create an update.
  • High Sierra (10.13), the current version of macOS, will be the last version to support 32-bit apps “without compromise.”

Starting on April 12th, macOS users will begin receiving messages indicating that apps installed on their system are 32-bit, and will require an update. The notification, which appears once per app, states that “This app needs to be updated by its developer to improve compatibility,” and points users to a support page on Apple’s website explaining the situation in further detail.

Apple indicated to developers at the 2017 Worldwide Developers Conference (WWDC) that High Sierra (10.13), the current version of macOS, will be the last version to support 32-bit apps “without compromise,” though the specific meaning of that terminology is, as of yet, unclear. It is possible that the next version of macOS will retain some limited compatibility with 32-bit apps. Further details about the changes are expected to be announced at WWDC 2018 in June.

OS X Leopard (10.5), released in October 2007, was the first version to introduce full support for 64-bit apps. Coincidentally, Leopard was the last version of the OS to support PowerPC-based Macs. While support for 64-bit Intel apps was not simultaneous with Apple’s transition to Intel-powered processors, support for 64-bit apps has existed for over a decade.

SEE: Interview questions: iOS developer (Tech Pro Research)

Despite that, a fair few apps for macOS still do not have 64-bit versions. For business users, the Blue Jeans and Cisco WebEx teleconferencing clients are still only available as 32-bit apps. Users can check the apps on their Macs to see which installed apps are 32-bit by opening the Apple menu, choosing “About This Mac,” and clicking the System Report button. From the system report, scroll down to Software, then select Applications. When you select an individual application, you will see a field titled “64-bit (Intel).” “Yes” indicates 64-bit; “No” indicates 32-bit.

Apple has had practice at deprecating legacy applications, as the same process was used for the 32-bit apps in iOS. First, Apple notified developers, and then users, and stopped accepting app submissions to the App Store that were not 64-bit, before finally removing support entirely. Presently, the App Store does not accept submissions of 32-bit apps for macOS.

Relatedly, a recent report noted that Apple is working on a long-term strategy to migrate iMac and MacBook products from Intel processors to ARM-based processors developed in-house, similar to the processors currently used on iPhone, iPad, Apple Watch and Apple TV products. The report–which first appeared in Bloomberg–indicates that the project, called “Kalamata,” would likely be a multi-step transition starting in 2020.