I looked aroound online and came up with:

History of Online Mafia Games:

part 1:

MafiaScum, however, is devoted to the online version of the game. As far as anyone knows, this version was first attempted in August 2000 on the Grey Labyrinth. It was so successful that mith (a regular GL-er) felt it warranted its own site. Online Mafia has the potential for more strategy and subtlety because it removes most of the possibility for cheating and provides players with a chance to form suspicion based on logic and voting patterns instead of facial expression. It also has the potential for just as many, if not more, laughs, because the players can act however they like, no matter how shy they might be in real life. (From Wiki)

The game of course was a staraight favourite, and was refined until there was millions of roles and themes and everyone couldn't keep track so its really popular now.

part 2: Coming later, read part 1 for now.
part 3: comign later, read part 2 for now.