There are a lot of relay implementations and yes some aren't being maintained.

nostr:npub180cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsyjh6w6 has four! khatru, pyramid, relay29, relayer.
nostr:npub1q3sle0kvfsehgsuexttt3ugjd8xdklxfwwkh559wxckmzddywnws6cd26p ditto,
My chorus
nostr:npub1mlekuhhxqq6p8w9x5fs469cjk3fu9zw7uptujr55zmpuhhj48u3qnwx3q5 replicatr
nostr:npub1xhfxu35se0s63x90v8xr29txr66l5a3m277skshy2zvu3ve0658sla4xw3 nostr-rs-relay
nostr:npub1yxprsscnjw2e6myxz73mmzvnqw5kvzd5ffjya9ecjypc5l0gvgksh8qud4 strfry
nostr:npub1qqqqqqyz0la2jjl752yv8h7wgs3v098mh9nztd4nr6gynaef6uqqt0n47m's nostream