Per my understanding: most important functionality is implemented in the client; clients can connect to any relay server, and any number of relay servers; messages can be relayed by any number of relay servers; and anyone can spool up a new relay server at any time.
I was able to get nostr-rs-relay[0] running in <5 minutes on fly.io. Got all my client apps and those of ~5 friends writing to and posting from it. Hasn't crashed yet.
