(I)IRC
If I Recall Correctly... The SciFi Channel (now SyFy) ran an Internet Relay Chat server at least as early as 1997 . I don't remember exactly when it launched, but I do know it was operational in December 1999 -- because I was logged in on New Year's Eve, spiting Y2K (sure to cause traffic lights to go haywire, hospitals to short-circuit, and planes to literally fall from the skies). The rooms were full of... well, nerds, of course, but particularly weird nerds; the server was much lower-populated than the sprawling IRC giants that would arise like Darknet or Xellium or... well, anyway, the point is, there were a handful of chat rooms which each catered to a specific set of about a dozen or so people, and this was (as far as anyone there knew) what was meant by the term "online community." I've been thinking of IRC lately because of the prevalence of the Slack chat platform, which does a good job of recreating a similar environment with a few more bells and...