FluxGarden is a proprietary tool for maintaining a digital garden developed and sold by Bill Seitz.
You get 2 gardens: 1 private ("inner") and 1 public ("outer"). (Under the same subdomain which you pick, like "alice.flux.garden".) Both spaces give you:
the same Markdown format, and double-bracket linking for Backlinks;
a nice front-page of most-recently-updated pages, with excerpt;
an RSS (Atom) feed.
The software looks great, but requires a subscription:
I'm not sure if it has an export function. If it does, I can say you can safely use it. Bill Seitz looks like a chill guy, but you know how it is with commercial centralized services. They all break eventually.