[hyggetrold]

I can't remember the name of it, but over a decade ago I saw something like this - it was a single Linux server shared by (I think) hundreds of people. Really trying to do the multi-user paradigm. They advertised it as a private kind of social network, it was invite-only and I think you had to pay to help keep the server lights on.

Hopefully by posting something incorrect, A Person On The Internet Who Knows Better will come along and provide the correct details. :)

[evah]

Tilde.club nearly meets your definition.[1] It's at least 1 decade and 15 days old, but it appears it's open to join for anyone.[2]

[1] https://tilde.club/ [2] https://medium.com/message/tilde-club-i-had-a-couple-drinks-...

[hyggetrold]

The first link you put gives me a security warning so I didn't click through. But the medium article would suggest that this is the one!

[hoppyhoppy2]

Maybe SDF?

https://en.m.wikipedia.org/wiki/SDF_Public_Access_Unix_Syste...

https://sdf.org/