This is a pretty nice way to lap all of your childhood computing nostalgia or satisfy your curiosity about the vintage computer world (if you were born in the smartphone era).
The software run on your web browser through an emulator. The Internet Archive has recently released a software library that has all the Macintosh software from the 80’s, specifically from 1984-1989. Well, it seems that your prayers have been answered. You think that those old GUI based systems were best for the day's work and wish they still existed as a separate system. The name Classic that now signifies the historical Mac OS as a whole. Windows and Linux platforms are also supported using the screen casting sender built into the Google Chrome browser. But there are times when you sit back and think about those good old days when simple “black and white” pixels were less complex and did the job perfectly, especially the applications and games form the Macintosh. The Classic Mac OS (System Software) is the series of operating systems.
Not only applications, even games these days could let you relish the World War 1 era in graphics that seem to be better than the real. We are in an age where computer programs are able to detect our behaviour and decide what’s best for us (AI assistants like Cortana and Siri).