FloatingRuins by DaftPVF, bspkrs
Floating islands taken from the ground with ruins on top.
worldgen ruins dungeons serverside opensource
Morpheus by Quetzi
Morpheus is a server-only mod that adds sleep voting to a forge based server. When a player sleeps, all other players in the same dimension are notified so it is easier to coordinate.
Server Tools by matthewprenger
Adds a variety of server utilities and commands
serverside util admin opensource