Every Mac operating system since 1984 boots in this tab

The tab loads and there it is, a full Mac OS 8 desktop, the platinum menu bar across the top, a hard-drive window open to folders named Games and Multimedia and Utilities, the clock reading some time in the late nineties. You can open programs. It is a Macintosh.

Infinite Mac, by Mihai Parparita, is a collection of classic Apple systems you boot straight from a link. The timeline runs from System 1.0 in 1984 all the way up through Mac OS X and even NeXTSTEP, dozens of releases in total, each one a real machine you can poke at instead of a slideshow of screenshots.

And boot means boot. The numbers in Parparita's launch writeup are a happy Mac on screen in about a second and a fully loaded desktop in three, on a cold cache. The physical machines never came close.

Seven emulators, one compiler

Here is how you get a Motorola 68K Mac running in a browser that has never heard of one. Infinite Mac takes the established Mac emulators, Mini vMac and Basilisk II for the 68K machines, SheepShaver and DingusPPC for the PowerPC era, PearPC for early Mac OS X, Previous for the NeXT hardware, plus the newer Snow, and compiles them all to WebAssembly with Emscripten. Seven cores in total, and the site picks the right one for whichever system you clicked. It is the same compiler that once squeezed Doom into a PDF file, here aimed at something gentler. Around the emulators sits a React and TypeScript app that draws the window chrome and the app library.

The disk story is the clever part. A period system folder plus a library of software would be a brutal download, so each disk image is chopped into fixed-size 256KB chunks, Brotli-compressed and named by their content. A service worker fetches a chunk from Cloudflare's storage the moment the emulated Mac reads that stretch of disk, with a little prefetching for sequential reads. You stream an operating system the way you stream a video.

There are quieter tricks underneath. An emulated CPU normally spins flat out doing nothing, so the emulator notices when the Mac goes idle and parks the thread on an Atomics wait, which lands the whole machine around 13 percent CPU while it sits there being 1996.

The detail that makes it feel alive is that files persist. Anything dropped in the Saved folder is written through to the browser's IndexedDB and survives between sessions, and you can drag a file in from your real desktop and watch it surface inside the emulated one. It is not a museum behind glass. It is a machine you can use.

The software library is its own archaeology. The disk images are assembled with a Python tool called machfs that speaks the old HFS format, filled from Internet Archive uploads and decompressed StuffIt archives, with Finder niceties like icon positions preserved on purpose.

Everything above comes from the repo and Parparita's blog, which documents each layer of the build as it happened. If the compile-anything-into-a-tab trick is the part that itches, the Emscripten tutorial takes you from a C file to a running page in an afternoon. Bring your own decade of Mac software.

More old computers with no hardware left: a full Linux box that runs with no server behind it.