The discovery of a change in file naming conventions in OS X 10.11.4 is behind a recent growth in speculation that Apple is set to rebrand its OS X desktop operating system.

Mac OS

Screenshot from Mac OS 8 released in 1997.

The rumor appears to have begun on Tuesday after Brazilian Apple blog MacMagazine reported that a name used for an Interface Builder document tucked away in the OS X System folder contained a previously unseen reference to 'macOS'.

Developer Guilherme Rambo discovered that a document in FlightUtilities.framework in /System/Library/PrivateFrameworks takes the name FUFlightViewController_macOS.nib, which it did not have prior to last week's release of OS X 10.11.4.

macOS reference

Image: Guilherme Rambo

Speculation appears to be based on the fact that iOS, watchOS, and tvOS already take similar naming conventions, leading some to believe that OS X could be set to fall in line.

However, as 9to5Mac points out, there are good reasons to remain skeptical that the change indicates an imminent rebrand.

Apple developers often use macOS identifiers for convenience, because the naming scheme suffix shares symmetry with Apple's other platforms and allows coders to easily identify apps with cross-platform components. Additionally, a significant rebrand of Apple's flagship desktop OS is the type of marketing decision that engineering teams would be unlikely to hear about until later on in the version cycle.

Despite the skepticism, a rebrand for OS X is by no means out of the question. Indeed, the name change would see Apple revert to the operating system's traditional name Mac OS, which remained in place until Apple dropped 'Mac' from its OS X branding in 2012.

The next version of Apple's Mac operating system, 10.12, is rumored to include Siri as a desktop feature, and is expected to be revealed at the Worldwide Developers Conference in June ahead of a public launch in the fall.

Update: The file is actually not new in OS X 10.11.4, as it is present on machines running older versions of OS X El Capitan and lists a creation date of August 2015.

Related Forum: macOS Sierra

Top Rated Comments

iZac Avatar
125 months ago
Hands up who still pronounces it "OS EX" despite knowing full well that it's "OS TEN"?

*raises hand*
Score: 37 Votes (Like | Disagree)
Ballis Avatar
125 months ago
So people are actually named Rambo? Thats awesome!
Score: 16 Votes (Like | Disagree)
rudychidiac Avatar
125 months ago
macos tacos
Score: 8 Votes (Like | Disagree)
JosephAW Avatar
125 months ago
Apple will rebrand OSX and use macOS when they roll out the new iMacs using the A10 desktop processors as they fade out the use of x86 chipset.
Score: 6 Votes (Like | Disagree)
Xeyad Avatar
125 months ago
Now bring back the Happy Mac! Am I too old that I remember this back when I had Mac System 6.0 on my Macintosh LC III?

Score: 5 Votes (Like | Disagree)
bbeagle Avatar
125 months ago
Bring back the Apple key on the keyboards! I have a Macbook Pro, and I'm still using an external keyboard that has the Apple key. When I use the laptop by itself, there is no Apple key. Small thing, but I wish it was still there.

Score: 5 Votes (Like | Disagree)

Popular Stories

iOS 26 Feature

iOS 26.1 to iOS 26.4 Will Add These New Features to Your iPhone

Saturday October 18, 2025 11:00 am PDT by
iOS 26 was released last month, but the software train never stops, and iOS 26.1 beta testing is already underway. So far, iOS 26.1 makes both Apple Intelligence and Live Translation on compatible AirPods available in additional languages, and it includes some other minor changes across the Apple Music, Calendar, Photos, Clock, and Safari apps. More features and changes will follow in future ...
ios 26 1 liquid glass opaque

iOS 26.1 Beta 4 Lets Users Control Liquid Glass Transparency with New Toggle

Monday October 20, 2025 10:57 am PDT by
With the fourth betas of iOS 26.1, iPadOS 26.1, and macOS 26.1, Apple has introduced a new setting that's designed to allow users to customize the look of Liquid Glass. The toggle lets users select from a clear look for Liquid Glass, or a tinted look. Clear is the current Liquid Glass design, which is more transparent and shows the background underneath buttons, bars, and menus, while tinted ...
iPhone Siri Glow

Some Apple Employees Have 'Concerns' About iOS 26.4's Revamped Siri

Sunday October 19, 2025 7:39 am PDT by
iOS 26.4 is expected to introduce a revamped version of Siri powered by Apple Intelligence, but not everyone is satisfied with how well it works. In his Power On newsletter today, Bloomberg's Mark Gurman said some of Apple's software engineers have "concerns" about the overhauled Siri's performance. However, he did not provide any specific details about the shortcomings. iOS 26.4 will...
iOS 26

iOS 26.0.2 Update for iPhones Coming Soon

Friday October 17, 2025 7:35 am PDT by
Apple's software engineers continue to internally test iOS 26.0.2, according to MacRumors logs, which have been a reliable indicator of upcoming iOS versions. iOS 26.0.2 will be a minor update that addresses bugs and/or security vulnerabilities, but we do not know any specific details yet. The update will likely be released by the end of next week. Last month, Apple released iOS 26.0.1,...
Apple iPad Pro hero M5

New iPad Pro Has Six Key Upgrades Beyond M5 Chip

Saturday October 18, 2025 10:57 am PDT by
While the new iPad Pro's headline feature is the M5 chip, the device has some other changes, including N1 and C1X chips, faster storage speeds, and more. With the M5 chip, the new iPad Pro has up to a 20% faster CPU and up to a 40% faster GPU compared to the previous model with the M4 chip, according to Geekbench 6 results. Keep in mind that 256GB and 512GB configurations have a 9-core CPU,...
maxresdefault

Here's How the iOS 26.1 Transparency Toggle Changes Liquid Glass

Monday October 20, 2025 1:55 pm PDT by
With the fourth beta of iOS 26.1, Apple added a toggle that makes Liquid Glass more opaque and reduces transparency. We tested the beta to see where the toggle works and what it looks like. Subscribe to the MacRumors YouTube channel for more videos. If you have the latest iOS 26.1 beta, you can go to Settings > Display and Brightness to get to the new option. Tap on Liquid Glass, then...
iOS 26

What's New in iOS 26.1 Beta 4

Monday October 20, 2025 1:02 pm PDT by
Even though we're at the fourth beta of iOS 26.1, Apple is continuing to add new features. In fact, the fourth beta has some of the biggest changes that we'll get when iOS 26.1 releases to the public later this month. We've rounded up what's new below. Liquid Glass Transparency Toggle Apple added a toggle for customizing the look of Liquid Glass. In Settings > Display and Brightness,...
HomePod mini and Apple TV

Apple's Next Rumored Products: New HomePod Mini, Apple TV, and More

Thursday October 16, 2025 9:13 am PDT by
Apple on Wednesday updated the 14-inch MacBook Pro, iPad Pro, and Vision Pro with its next-generation M5 chip, but previous rumors have indicated that the company still plans to announce at least a few additional products before the end of the year. The following Apple products have at one point been rumored to be updated in 2025, although it is unclear if the timeframe for any of them has...