Forager
Co-op for Forager, made by melogo5. A host and up to three guests share one world: resources, mobs, buildings, chests, bridges and the time of day. You need Forager on Steam, build 4.1.9 only, and only Classic worlds work. Forager's own Mod API mods are not supported. The author calls it a beta: some things can still go out of sync.