Enthusiastic programmers create many websites that, thanks to the development of computing power and the capabilities of Internet browsers, can run not only previously very demanding desktop applications (for example Photopea etc.), but even entire operating systems.
And just one such enthusiast – Mihai Parparita created on the web macOS8.app Apple’s fully operational 1997 operating system, back from when Steve Jobs had just returned to Apple.
Of course, he did not create the emulation completely himself, but built the entire system on the many critical components already developed that allow something like this. It is not just an emulation of an empty operating system, there are all the different applications, lots of games or even the HyperCard development system, with which almost everyone could create programs at that time, easily and quickly.
You can read how macOS 8.1 was created in a browser on the blog creator. The fact that you can get your own files to your computer and download them from your computer proves that this is not an empty tinsel. The system supports dragging files directly to the desktop. The entire source code is also available solution on github. If you want even more into the past, it is created by the same author as well system7.app.