Defining the first MMO is pretty tricky. It was an evolutionary progress, limited by the hardware of the time. There are games which back in the 80s counted as the MMOs of their day when you can have more players in a FPS game today. Probably some MUD at some point crossed a rather arbitrary line that makes it the first MMORPG but pinning that line and that point down is going to be subjective.

Oh, and the Neverwinter Nights that is cited as the first MMORPG is not the same game as the one BioWare made.