The updates' appearance signalled that Apple is just weeks away from introducing their successors, OS X El Capitan and iOS 9. The latter will almost certainly be unveiled September 9, the best-guess date for Apple's debut of new iPhones, while the former may release to customers shortly after.
The Mac's operating system update, pegged as 10.10.5, boasted a short list of reliability and compatibility improvements to Yosemite's baked-in Mail, Photos and QuickTime Player apps. Meanwhile, iOS 8.4.1 focused on bug fixes for the new Apple Music, the subscription-based streaming music service the company kicked off June 30. Both also featured dozens of vulnerability patches.
Yosemite 10.10.5's arrival pointed to an earlier-rather-than-later release of El Capitan, aka OS X 10.11.
Over the last two cycles, Apple has released the fifth -- and final -- non-security update of its then-current Mac operating system five to six weeks before the successor goes public. Last year, for instance, Mavericks final non-security update, 10.9.5, made the scene on Sept. 17, or 29 days before Yosemite's launch. In 2013, the fifth non-security update for Mountain Lion reached users 40 days before Mavericks' release.
If Apple hewed to the same schedule, El Capitan would materialize between Sept. 11 and Sept. 22, or about a month earlier than the last two upgrades.
There have been other clues that Apple may beat the calendar with El Capitan: Its developer preview build release tempo has accelerated in the last month, with three versions since July 21.
Apple also issued what was likely the final security update for OS X Mountain Lion, patching 33 vulnerabilities in the three-year-old operating system.
OS X 10.10.5 (Yosemite) and Security Update 2015-006 (Mountain Lion and Mavericks) can be downloaded from Apple's website or installed using the operating system's built-in update service.