I was just perusing some of the data over at Mudstats.com, and I thought I should bring some of it up as it's rather interesting if you happen to be a mud enthusiast like myself.
This of course is only for Muds registered @ Mudstats:
As of 8 pm this evening there were just shy of 11,000 people playing MUDs.
Over 4000 of them were playing "Other" codebases, which is more often then not DIKU and it's derivatives.
Just over 4000 of them were playing Fantasy based MUDs, followed by Furry(1100), Adult(1000), and Social(700).
Mudstats lists 838 "Active" MUDs, while boasting roughly 600 with an on-line player count of 0("Non-active").
Of the 838 "active" MUDs, roughly 20 have a player count of 100+, while roughly 600 have a player count between 1-5.
tbaMUD developer/programmer