Forget Ventura, you can run Mac OS 9 on your new Mac

Software engineer Mihai Parparita is at it again. After previously turning macOS 8 and earlier versions of Apple’s Mac OS into workable web apps, Paparita has released a new Mac OS emulator for the dearly departed Mac OS 9 at macos9.app. As part of his Infinite Mac series, Paparita takes old versions of the Mac operating system and engineers them so they run within a web browser.

When Mac OS 9 loads, one characteristic of the OS immediately stands out: It takes a long time to boot, which Parparita attributes to the “bloat in Mac OS 9 itself.” But once it’s up and running, the emulated Mac OS is surprisingly functional, and you can get actual work done with the included apps, including Microsoft Word, ClarisWorks, Adobe Photoshop, and KidPix.

Parparita’s Infinite Mac series includes system6.app, system7.app, and macos8.app for System 6, System 7, and Mac OS 8, respectively. As we wrote last year, the Mac OS 9 emulator has similarly faithful functionality to the original that allows you to create files and export them to your modern Mac. To bridge the worlds, Parparita created a “server” called The Other World that lets you drag and drop files to transfer them between the emulator and your modern Mac.

Here’s one important tidbit to know if you’re planning to use macos9.app or the other emulators to do actual work. Pressing Command-W closes the browser window, not the window in the emulator, which may seem obvious to your brain but not your fingers. So if you are, say, writing an article about Parparita’s work in the macos9.app’s Nisus Writer and instinctively press Command-W to close the window you’re working in, you’ll close the entire browser window and lose all of your work. Be warned and save yourself from the aggravation I experienced first-hand while writing this.

Mac OS 9 was the last classic OS before Apple transitioned into the OS X series with a brand-new Unix-like system. When Apple introduced OS X.2 Jaguar at WWDC in 2002, Steve Jobs held a funeral for Mac OS 9, stating that “we say farewell to OS 9 for all future development, and we focus our energies on developing for Mac OS X.” And now 20 years later, it’s back from the dead.