It also has attainable player ranks, such as Settler, and Aristocrat. You start off with the rank 'Nomad' and after you play for 24 hours you attain Settler.
Settler is a rank that shows you have been playing for a while, and are most likly better off than the nomads.
Aristocrat is a rank you must apply for, is accepted for this rank you may sell items for emeralds. You may also host MCCMO parties, in witch you can exchange XP.
Emeralds pretty much run the economy, you can make emeralds for trading items with villagers, then you may buy valuable items, such as Iron, Diamonds, Food, and pretty much anything you can think of.
But unlike most other servers it's not a game with rounds, or totally themed around one thing, this makes it really different and special from other servers.
Everything else has pretty much been stated above, these things are what makes Elysium unique, and the best Survival Multiplayer game ever.