This is really impressive. It's exactly what I imagined the original Microsoft Network in Windows 95 would have been like. And so The Microsoft Network wasn't a program you loaded like CompuServe. It was part of the OS, with folder icons that looked just like real folders. It was a kind of version of the Web where you could browse online data the same way you browsed your file system. This is what made it cool. It wa…
Nowadays we call those APIs. They are REST based rather than file-based to make them distributed, the main difference is that you don't get a common user interface that all providers adjust to; you need to choose your own client to read them and write into them.
And because they're created by programmers for programmers, they're not what you'd call user-friendly. Usually the only efficient way to use them is programmatically, so that you need to create a specific user interface for each API. Somehow, I doubt that Cairo would have come to be anything much different from that in the end.