I was a member, bought back my soul, and had a hell.com email address for years. As aric said, it was a cabal of artists and designers, mostly using Flash. There were discussion boards, spaces to explore, and so on.

The associated site http://www.cygne-noir.com/ is still up, but with just an image. There's probably a login somewhere, but you must know the URL. And http://final.org/ is for sale. But http://www.8081.com/home/ and http://www.medialounge.org/ are still there, and seem much as I recall.

Exploring past those gates into membership is rumored to have led to a cabal of artists and designers in the web's avant-garde scene. We may remember hell.com for what it represented. It was a rabbit hole that unsettled minds, unfurling beyond depths of a web people previously thought they knew, to cause wonder.