If you’ve been a longtime Mac user, you may fondly remember the classic Mac OS system software releases. Rather than get stuck in a memory, you can relive some nostalgia by running Mac OS 8.1 on your modern Mac right now (or even on a Windows PC or Linux machine), and it’s as easy as launching any other app.

Macintosh.js is a self-contained Electron app that bundles a classic Mac OS emulator preinstalled with Mac OS 8.1 along with a handful of classic applications from that era, including Adobe Photoshop 3.0.5, Adobe Illustrator 5.5, demos for Duke Nukem and…