The app is an Electron-based emulation of a Quadra 900 (released in 1991) with a Motorola CPU before the Mac switched to the PowerPC architecture, and runs standalone on Windows, macOS and Linux.
There's very little you can do with only the OS, but this app comes pre-installed with a variety of software from the 1997 MacWorld demo CD. It includes games such as Oregon Trail and Civilization 2, as well as practical applications and trial versions of Adobe Photoshop 3, Premiere 4, Illustrator 5.5, StuffIt Expander, and Apple Web Page. Files can be transferred directly through the host machine, and disk images can be mounted for external data transfer.
But as for the web, the system is completely different than it was about 30 years ago, and now it can''t even open Google. Internet Explorer and Netscape (both of which were products at the time) can be installed along with the "Web Sharing Server".
As it is a direct reproduction of Apple's operating system, it's probably the rights that are concerned. The license states that it is provided "for educational purposes only" but has not been approved by Apple.
However, since all apps must be notarized by Apple on macOS Catalina (after February 2020), which is one of the operating environments, the company has probably tacitly approved it. However, it's not officially sanctioned, so if you want it, you might want to download it as soon as possible.
This article is based on an article from the Japanese edition of Engadget and was created using the translation tool Deepl. The Japanese edition of Engadget does not guarantee the accuracy or reliability of this article.