Afterglow emulates After Dark screen savers on macOS — no ROMs, no classic Mac OS

Afterglow is a purpose-built emulator that revives Berkeley Systems’ After Dark screen savers — the Flying Toasters, swimming fish, and surreal desktop antics that defined 1990s Macintosh culture. Rather than remaking or porting the animations, it executes the original 68k module code directly, sidestepping the burn-in-prevention utilities’ original purpose and treating them instead as software artifacts worth preserving. Until now, running these modules meant wrestling with finicky Mac OS emulators or hunting down vintage hardware, and even then no single setup ran every module at its intended speed.

The technical hook is that Afterglow needs no Apple ROM or classic Mac OS installation. It leans on the open-source Musashi 68k CPU emulator and reimplements just enough of the Macintosh Toolbox and OS APIs to keep the modules running. Users supply their own modules — the app doesn’t bundle them — but importing is drag-and-drop, accepting raw module files, disk images, and compressed archives, and it can pull software releases directly from the Internet Archive in-app.

Beyond the core emulator, Afterglow ships a native macOS screen saver module so imported classics can run as a real lock screen or idle display, plus extras like full-screen and randomizer modes, multimodule playback, a CRT shader, 3D box art, a resource inspector, and a DrawMorph editor. It’s a small but pointed example of the preservation-through-emulation approach: keeping decades-old, platform-locked software runnable without the original hardware or OS.