The many names of Apple’s operating systems, from System 1 to macOS


The many names of Apple’s operating systems, from System 1 to macOS

It’s been 40 years since the Apple Computer Inc got its start, and to celebrate this momentous occasion, it has renamed (or reverted, as we will see) its flagship personal computer operating system: OS X is now macOS.

That’s only the latest change in a rather confusing few decades that saw the OS changing its look and name to suit both trends and the whims of leadership. Shall we start at the beginning?


Apple DOS and Apple SOS

The early Apple I and II computers ran a variety of custom Disk Operating Systems, and with the Apple III came Apple SOS — originally named “Sara’s” Operating System, but later changed to “sophisticated.” It added several important features but sunk along with the ill-fated III.


Apple Lisa

In early 1983 came the Lisa, which of course stood for Local Integrated Software Architecture — but also happened to be the name of Steve Jobs’s daughter. While the Lisa was the first experience many would have with a real GUI, it was expensive and unreliable, and it wasn’t long before the Macintosh came and ate her lunch.


System 1.0 through System 7.0

The first Apple Macintosh, shown off in January of 1984, ran version 1.0 of the OS known simply as “System” at the time. Over the next few years, Systems 2-7 piled on features but retained the workmanlike nomenclature.


System 7.1.1 Pro

System 7.1.1 is not particularly notable for what it added to the OS, but it is the first Apple product to use the “Pro” suffix — although it was an isolated incident and wouldn’t appear again for years. This slide is just for the record.


System 7.5.1

In the brief era of Mac clones, System 7.5.1 included a change intended to make it clear just what kind of computer you were booting up. The familiar Mac OS logo would endure for years, and the two-tone face does to this day as the Finder logo — with some minor updates, of course.


Mac OS 7.6

With 7.6, Apple left “System” off entirely, cutting the cord with the early Macs.


OS X Public Beta "Kodiak"

Wait, Kodiaks aren’t cats! Yes, the public beta for OS X was known internally as Kodiak — the name didn’t appear anywhere else, but it’s a nice little factoid you can probably win a bar bet with.


Mac OS X 10.0 and 10.1

You could be forgiven for failing to remember that the first real version of Mac OS X — and it was still Mac OS X at the time — was codenamed Cheetah. After all, Apple didn’t use that or Puma, the name for 10.1, in marketing materials or the like. For the duration of 2001, it was just “ten” or “ten point one.”


Mac OS X 10.2 through 10.7

Enthusiasm for the big cat code names of 10.0 and 10.1 prompted Apple to start using them openly. Who can forget the furry, dappled X of Mac OS X 10.2, Jaguar?

See if you can remember the next few. We’ll wait…

After Jaguar came Panther, then Tiger, Leopard, Snow Leopard, and Lion. Next came…


OS X 10.8 "Mountain Lion"

Notice something different about the name? No, not the cat. There’s no “Mac” in front of “OS X.” Mountain Lion was the first release where Apple lost the Mac name, if only from the OS itself.


OS X Mavericks

Fearing that a lack of cool cat-based names might delay development of the OS, Apple moved on to naming OS X releases after notable locations in California, the company’s home state. The nickname also received a promotion in the “About this Mac” window.


macOS Sierra

At WWDC 2016, Apple slyly changed the name of OS X (version 10.12, if anyone’s counting) to be more in line with its other products, iOS and watchOS — thinking nothing, as usual, of the reporters who would have to make the hard decision of whether to capitalize it at the beginning of a headline. Thanks for that, Apple.