Back when Ars Senior Products Editor Andrew Cunningham was forced to work in Mac OS 9 by his colleagues in September 2014, he quickly hit a productivity wall. He couldn't log in to his Ars e-mail or do much of anything online, which meant—as someone who writes about new technology for an online-only publication—he couldn't do his work. All Cunningham could do was play old games and marvel at the difference 15 years makes in operating system design.

But as hard as it may be to believe in light of yet another OS X macOS update, there are some who still use Apple's long-abandoned system. OS 9 diehards may hold on due to one important task they just can't replicate on a newer computer, or perhaps they simply prefer it as a daily driver. It only takes a quick trip to the world of subreddits and Facebook groups to verify these users exist.

Certain that they can't all be maniacs, I went searching for these people. I trawled forums and asked around, and I even spent more time with my own classic Macs. And to my surprise, I found that most of the people who cling staunchly to Mac OS 9 (or earlier) as a key component of their daily—or at least regular—workflow actually have good reason for doing so.

Why? Whhhhyyyyyy???

The reasons some Mac lovers stick with OS 9 are practically as numerous as Apple operating systems themselves. There are some OS 9 subscribers who hold out for cost reasons. Computers are prohibitively expensive where they live, and these people would also need to spend thousands on new software licenses and updated hardware (on top of the cost of a new Mac). But many more speak of a genuine preference for OS 9. These users stick around purely because they can and because they think classic Mac OS offers a more pleasant experience than OS X. Creatives in particular speak about some of OS 9's biggest technical shortcomings in favorable terms. They aren't in love with the way one app crashing would bring down an entire system, but rather the design elements that can unfortunately lead to that scenario often better suit creative work.

I'm alluding here specifically to the way OS 9 handles multitasking. Starting at System 5, classic Mac OS used cooperative multitasking, which differs from the preemptive multitasking of modern Windows and OS X and Linux. With classic Mac OS multitasking, when you want to change apps it's up to the active program to relinquish control. This focuses the CPU on just one or two things, which means it's terrible for today's typical litany of active processes. As I write this sentence I have 16 apps open on my iMac, some of which are running multiple processes and threads, and that's in addition to background syncing on four cloud services.

By only allowing a couple of active programs, classic Mac OS streamlines your workflow to closer resemble the way people think (until endless notifications and frequent app switching cause our brains to rewire). In this sense, OS 9 is a kind of middle ground between modern distraction-heavy computing and going analog with pen and paper or typewriter.

These justifications represent just a few large Mac OS 9 user archetypes. What follows is the testimony of several classic Mac holdouts on how and why they—along with hundreds, perhaps thousands of people around the world—continue to burn the candle for the classic Macintosh operating system. And given some of the community-led developments this devotion has inspired, OS 9 might just tempt a few more would-be users back from the future.

Programmatic hangers-on

Remembering how the comments on Cunningham's article were littered with stories of people who still make (or made, until only a short time beforehand) regular use of OS 9 for getting things done, I first posed the question on the Ars forums. Who regularly uses Mac OS 9 or earlier for work purposes? Reader Kefkafloyd said it's been rare among his customers over the past several years, but a few of them keep an OS 9 machine around because they need it for various bits of aging prepress software. Old versions of the better-known programs of this sort—Quark, PageMaker, FrameMaker—usually run in OS X's Classic mode (which itself was removed after 10.4 Tiger), though, so that slims down the pack of OS 9 holdouts in the publishing business even further.

Wudbaer's story of his workplace's dedication to an even older Mac OS version suggests there could be more classic Mac holdouts around the world than even the OS 9ers. These users are incentivized to stick with a preferred OS as long as possible so they can use an obscure but expensive program that's useful enough (to them) to justify the effort. In Wudbaer's case, it's the very specific needs of custom DNA synthesis standing in the way of an upgrade.

"The geniuses who wrote the software we have to use to interface the machines with our lab management software used a network library that only supports 16-bit machines," he wrote. This means Wudbaer and colleagues need to control certain DNA synthesizers in the lab with a 68k Mac via the 30-year-old LocalTalk technology. The last 68k Macintosh models, the Performa 580CD and the PowerBook 190, were introduced in mid-1995. (They ran System 7.5.)

This DNA synthesis lab has two LC III Macs and one Quadra 950 running continuously—24 hours a day, seven days a week—plus lots of spare parts and a few standby machines that are ready to go as and when needed. The synthesizers cost around 30,000-40,000 Euros each back in 2002 (equivalent to roughly $35-50k in 2015 terms), so they want to get their money's worth. The lab also has newer DNA synthesizers that interface with newer computers and can chemically generate many more oligonucleotides (short synthetic DNA molecules) at once. This higher throughput comes with a tradeoff, however. Whereas the old synthesizers can synthesize oligonucleotides independently of each other (thereby allowing easy modifications and additional couplings), the new ones do them all in one bulk parallel process, meaning the extra stuff has to wait until afterward. More work means more time, and as Wudbaer says, "time is money."

On the Facebook group Mac OS 9 - it's still alive!, people trade more of these OS 9 endurance stories. Some prefer it for writing environment. Others keep it around for bits and pieces of work that require expensive software such as Adobe's creative suite or a CAD package or Pro Tools or specifically to open old files created with this software. Most use it for old Mac games, of which there are far more than the Mac's game-shy reputation would suggest—but that's a story for another day. A scant, brave few not only struggle through OS 9 for these sorts of offline tasks, but they also rely on it as a Web browsing platform.