What I meant is how did he accomplish that? For the better part of a decade people have been posting suggestions to make the game multiplayer, only to be rebutted with replies on the lines of 'it's impossible', 'games have to be built from the ground up for this to work', 'it would require years of work and rewriting', and so on. So to say I'm surprised that someone just shows up and drops a couple scripts that make it possible is an understatement.
They were talking about something
completely different. What people were saying was "impossible" was each person running their
own actual copy of Dwarf Fortress fortress mode, running an entire fortress yourself, but all the fortresses being part of the same "world" somehow, e.g. able to send armies to other player's fortresses, or being able to switch into adventure mode and go visit someone else's running fortress. This is what they were refering to, and it is what is
still impossible for all practical purposes.
We've been able to have multiple people remotely log into a
single copy of DF for frikkin' years now. however, the limit is that everyone was basically controlling the same fortress at the same time. So it was in fact more on the level of "twitch plays DF" than having separate players. What Warmist seems to have done is taken the that idea but added external logic so that each player who logs in has separate controllable units in the game, probably using DFHack and other tools to interface into the game. This could get pretty creative, however the core limit is that you all need to be part of the same running fortress on one person's computer. So it's effectively a layer where each person has a little input into one game, rather than everyone running their own game.
Even though these can both be refered to as "dwarf fortress multiplayer", they refer to completely different things.