Some like names, others prefer numbers. Look at cars: there are marques like Peugeot who have been numbering each of their models since they started mass-producing the 201 in 1929, while others like Ford have generally used letters or names. The latter have proved far more evocative: a Ford Mustang or Capri wins hands down over a Peugeot 205 GTI 1.9.

Although Apple’s operating systems have used various forms of version numbering, and add to the confusion with separate build numbers, it has always preferred names. Formally, until 2001 when it released Mac OS X 10.0 Cheetah, no operating system for Macs had a public name. Up to 7.5, they were simply known by version, as in System 7.1, then became Mac OS 7.6 and later. But internally each had at least one project name. System 7.0, a major landmark in classic days, was appropriately called Big Bang, or alternatives such as Blue and Pleiades, if you preferred references to the classics.

I don’t think Apple really intended to start giving public names to major versions of Mac OS X, but it happened with Cheetah, and once that had become popular, naming them after big cats became an expectation if not a commitment. By OS X 10.8 Mountain Lion, Apple was fast running out of felids, and didn’t fancy Cougar, Ocelot or Lynx, so for OS X 10.9 it switched to place names on the US West Coast. Macs had gone from a bestiary to a geography.

Those have proved an education for me and others who aren’t familiar with many locations in California. Starting with the story of the naming of Mavericks Beach and its reputation for big wave surfing, we’ve worked our way through 13 fascinating local histories, and some of the most spectacular views for what is now inappropriately termed Wallpaper. From a personal point of view, those names have also formed the basis of some deviously cryptic riddles.

Apple, though, still can’t resist having its own internal project names. Apparently, Sequoia was known as Glow, and Tahoe most inauspiciously as Cheer. I don’t think that cheer lasted too long after its release to developers a year ago.

Today developers are arriving ready for tomorrow’s start of Apple’s Worldwide Developers Conference, held at Apple Park, Cupertino, and there have been ample rumours circling as to what will be revealed. Perhaps the safest, as Apple has all but preannounced them, are the first developer beta-releases of the next major versions of its operating systems, now coordinated into the single number 27. We already know macOS 27 will be the first version to be delivered only for Apple silicon Macs, but from there everything about it is speculation.

A couple of days ago I read a rumour that macOS 27 may be the first Mac operating system to come without a name since Mac OS 9.2 in 2001, although even that had the project name of Moonlight, with Limelight following as 9.2.1. How could Apple possibly do that?

Of course macOS 27 will have a name. I’m sure that it has long had a project name, probably for the last couple of years or more. Apple is addicted to naming features and subsystems within its operating systems. You only have to look at incomplete indexes to those, such as this at the Apple Wiki, to realise how pervasive that naming is. From Absinthe, for attestation, to Xavier, iOS private frameworks of unknown function, everything must have a name, and the more obscure the reference, the better.

Should Apple really not intend giving macOS 27 a public name, then it won’t go without one for long. If its internal project name isn’t known, then it’s up to us to give it our choice of name, which might not coincide with Apple’s intentions. But I’m afraid if Apple thinks I’m going to be writing about a mere version number, when we’ve enjoyed all those wonderful names over the last 25 years, then it doesn’t understand its public.

One way or another, tomorrow we will know the name of macOS 27.