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
127 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
127 months ago
So people are actually named Rambo? Thats awesome!
Score: 16 Votes (Like | Disagree)
rudychidiac Avatar
127 months ago
macos tacos
Score: 8 Votes (Like | Disagree)
JosephAW Avatar
127 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
127 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
127 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

Apple Wallet ID Illinois

Apple Plans to Expand iPhone Driver's Licenses to These 7 U.S. States

Wednesday December 24, 2025 8:40 am PST by
In select U.S. states, residents can add their driver's license or state ID to the Apple Wallet app on the iPhone and Apple Watch, and then use it to display proof of identity or age at select airports and businesses, and in select apps. The feature is currently available in 13 U.S. states and Puerto Rico, and it is expected to launch in at least seven more in the future. To set up the...
iPhone Top Left Hole Punch Face ID Feature Purple

iPhone 18 Pro Launching Next Year With These 12 New Features

Tuesday December 23, 2025 8:36 am PST by
While the iPhone 18 Pro and iPhone 18 Pro Max are not expected to launch for another nine months, there are already plenty of rumors about the devices. Below, we have recapped 12 features rumored for the iPhone 18 Pro models. The same overall design is expected, with 6.3-inch and 6.9-inch display sizes, and a "plateau" housing three rear cameras Under-screen Face ID Front camera in...
maxresdefault

Where's the New Apple TV?

Monday December 22, 2025 11:30 am PST by
Apple hasn't updated the Apple TV 4K since 2022, and 2025 was supposed to be the year that we got a refresh. There were rumors suggesting Apple would release the new Apple TV before the end of 2025, but it looks like that's not going to happen now. Subscribe to the MacRumors YouTube channel for more videos. Bloomberg's Mark Gurman said several times across 2024 and 2025 that Apple would...
maxresdefault

10 Mac Apps Worth Trying in 2026

Wednesday December 24, 2025 9:27 am PST by
2026 is almost upon us, and a new year is a good time to try out some new apps. We've rounded up 10 excellent Mac apps that are worth checking out. Subscribe to the MacRumors YouTube channel for more videos. Alt-Tab (Free) - Alt-Tab brings a Windows-style alt + tab thumbnail preview option to the Mac. You can see a full window preview of open apps and app windows. One Thing (Free) -...
iOS 26

iOS 26.2 Adds These 8 New Features to Your iPhone

Monday December 22, 2025 8:47 am PST by
Earlier this month, Apple released iOS 26.2, following more than a month of beta testing. It is a big update, with many new features and changes for iPhones. iOS 26.2 adds a Liquid Glass slider for the Lock Screen's clock, offline lyrics in Apple Music, and more. Below, we have highlighted a total of eight new features. Liquid Glass Slider on Lock Screen A new slider in the Lock...
airpods color prototypes

Apple Tested AirPods in Bright Colors

Saturday December 27, 2025 6:06 am PST by
Apple reportedly tested a version of the first-generation AirPods with bright, iPhone 5c-like colored charging cases. The images, shared by the Apple leaker and prototype collector known as "Kosutami," claim to show first-generation AirPods prototypes with pink and yellow exterior casings. The interior of the charging case and the earbuds themselves remain white. They seem close to some...
iPhone Fold Vertical Feature

Why Apple's Foldable iPhone May Be Smaller Than Expected

Tuesday December 23, 2025 5:21 am PST by
Apple's first foldable iPhone, rumored for release next year, may turn out to be smaller than most people imagine, if a recent report is anything to go by. According to The Information, the outer display on the book-style device will measure just 5.3 inches – that's smaller than the 5.4-inch screen on the ‌iPhone‌ mini, a line Apple discontinued in 2022 due to poor sales. The report has led ...
iPhone SE Cosmopolitan Clean

Apple Discontinued These 25 Products This Year

Wednesday December 24, 2025 7:24 am PST by
With the end of 2025 near, the time has come to look back at the devices and accessories that Apple discontinued throughout the year. Most of the products that were discontinued this year were simply replaced by a new model with an updated chip. However, the iPhone SE line was entirely discontinued when the iPhone 16e launched, and the iPhone Plus line is being phased out. Below, we have...
Foldable iPhone 2023 Feature Iridescent Search

Samsung Developing 'Wide Fold' With iPhone Fold-Like Design Ahead of Apple's 2026 Launch

Tuesday December 23, 2025 11:55 am PST by
Samsung is working on a new foldable smartphone that's wider and shorter than the models that it's released before, according to Korean news site ETNews. The "Wide Fold" will compete with Apple's iPhone Fold that's set to launch in September 2026. Samsung's existing Galaxy Z Fold7 display is 6.5 inches when closed, and 8 inches when open, with a 21:9 aspect ratio when folded and a 20:18...