In the beginning there was a council of three almighty jellies. The first lived off of the coast of Korea, and was subsequently eaten. The second, not being eaten, felt that knowledge should be had by all, and that those whom sought such knowledge shouldst have a place in which to acquire it. By mustering all of his power he forged the internet itself. Resting dormant awhile he was able to put the last of his strength into registering the domain fluther.com. From this point he entrusted the duties of management to the jelly overlords, those whom we name ‘moderator’.
The third did dwell in the deep places of the earth. Twisted and evil by the passage of time itself. Still, he lay in dreaming. But beneath the waters of the seas he was disturbed; the moon and the winds wrought havoc with his ocean. Awakened once more, he struck terror into the minds of men. Restless, ever anxious. He doth preside in in all places dark and shadowed. The sole reason all of mankind may never truly rest, for he awaits us. Wanting only to drive us mad. He is the great old one, and truly has he awoken.
Also, to be less silly, I believe it started in roughly 2006 (please correct me if I’m wrong, that’s just the first I recall hearing about it, and I can’t find a source) when someone wanted to know what a group of jellyfish was called. So they wanted to have a website where questions like that could be asked. I came here as a refugee after the answerbag crisis a few years back.
Super-sneaky ninja-edit: Don’t know why I said 2006 originally, I only heard about it in 2008.