I know this exact comment gets posted so often, but it's crazy how things my brain muses about magically appear on HN. I'm a long-time MUD enjoyer (played one semi-religiously for about 10 years) and have spent lots of time tinkering around with my own MOO implementations. Recently, BEAM languages have been getting a lot of attention, so naturally my mind drifted to the possibility of writing a MOO on top of BEAM that takes advantage of the immutability/concurrency/whatever.