While many might not know, the Dream SMP server is actually a group of people roleplaying a storyline within the world of Minecraft.

The Dream Survival-Multiplayer ("SMP") is a whitelisted multiplayer server best known for its complex improvisational plot, and history of factions, wars, alliances, and betrayals.

Dream SMP, which stands for Survival Multiplayer, is (according to its wiki page) a private, whitelisted Minecraft server played on mostly by the Dream Team.