The software was written by mostly teenagers and by all modern metrics was absolutely atrocious. Just to be clear all this was legal, it merely took on the visage of 'illegal' because it violated the TOS of the game and could you your in-game character(s) banned. Virtual currency could then be transferred over a 'black market' forum, usually with paypal as a medium. Bots would autonomously play characters in the game in order to 'farm' items that could be sold to other players in the game.
As a teenager I ran a pretty high margin business operating botting software for a popular MMORPG.
