amcchord/classicmac

ClassicMac is a native macOS app for Apple Silicon that lets you run the entire classic era of Mac OS, from System 7.1 through Mac OS 9.2.2, in emulated old Macintosh hardware. It wraps a customized build of QEMU, the open source emulator, inside a SwiftUI app, and emulates two specific machines: a Motorola 68040 based Quadra 800, and a PowerPC based Power Mac G4. Everything needed to run these emulated machines, including the emulators themselves, firmware, and video and folder sharing drivers, is bundled into the single app, so nothing needs to be installed separately with Homebrew or inside the emulated machine. You still need to supply your own copy of classic Mac OS to install, which the README points out is available from an online library that archives old operating systems. The project credits several other open source projects and individual engineers whose emulator patches and drivers it builds on, covering things like an enhanced video framebuffer, virtual drivers for folder sharing and floppy disks, and audio support. Notable features include live window resizing, where dragging the emulator's window to a new size actually changes the emulated Mac's screen resolution in real time, support for very high resolutions and full color depths on the Quadra machine, folder sharing between the host Mac and the emulated one that preserves classic Mac file metadata, support for writable virtual floppy disk images, and working sound on both machines. Each virtual machine is saved as a single self contained document that bundles its configuration, disk image, and settings, so it can be moved between computers or kept anywhere on disk. To get started, you download the packaged app, drag it into Applications, and use a plus button to create a new virtual machine, choosing which classic Mac model, disk size, memory, and resolution you want, then attach an install disc image you have downloaded separately and boot from it. The app is distributed as a signed and notarized disk image, so it opens without security warnings even offline. The README does not state a software license.