Scuttlebutt is hostless: each computer installs the same copy of software and has equal rights in the network.
While there are public peer servers, they are identical to the client peers rather than a special role. We feel that this doesn't make it not a peer to peer protocol, since anyone can run them, and your identity is not tied to them as in email@domain.
Devices discover each other over the LAN with multicast UDP and sync automatically.