Rise started as a simple RolePlay on some remote and obscure Forum lost in the deepness of the internet. Then, as the creator expressed, something spectacular happened to him. You see, the RP had a basic and simple backstory, it didn't have much depth beside the setting and some characters. Then the players created characters with various origins, species, some with unusual feats or just weird ones that look like girls. It went on to have more and more background, creating an interesting universe that is still expanding way beyond the original RolePlay.
Whoever wants to expand can do it.