From what I know, it advanced the functionality of Multiplayer, like admin teleporting, protections maybe, commands, stuff like that. I'm not sure though. Google it.
I'm searching for a good seed.
I found one that was nothing but median sized islands. need to figure out what it was. I think that'd be fun since we'd all claim our own mini continents.
I also would love to see a collaborative effort to build a town, complete with all of the resources one would have in their home like a Foundry, collective storage, collective mine, etc. It's lonely playing next to people, I think we should play together more collaboratively. We might build something worth showing on youtube.
EDIT: the seed for the medium sized island world is blobbystu (or the number 836618496) and here's a map of what it looks like.