“Flexible Survival” seems to be inspired on an existing MUD. It appears to be updated almost every day, and collaboratively - the code seems to be arranged entirely as Inform 7 extensions. The version in the archive is version 24, but you can download version 42 from the site.
I haven’t really played it yet, just browsed. It seems enormous in scope and in ambition. I’m very surprised never to have heard of it before - surely it warrants some attention from the community proper, if for nothing else then to just acknowledge the tremendous effort.
“Flexible Society” seems to be a spinoff of sorts.
I hate having to write “seems to be” so often, but this really isn’t geared for outsiders, and very little explanation is offered.
You’re exactly right, it was created outside the IF community, in the mu* (i.e. roleplaying and social mud) scene, but more than that square in the furry community, which really is its own thing. Kind of like how you don’t hear much about AIF in IF conversation.
I follow another mud forum where the developer posts regularly. I agree, it’s a very interesting game from what I’ve read and warrants more attention.
AND it’s a furry thing. Amazing. So that explains why it’s so sparse on up-front information - it’s for very specific circles, and assumes that people who want to play it are quite familiar with what it is.