FXX is preparing to air the longest marathon in TV history. After acquiring every last episode of The Simpsons last fall for a cool $750 million, the young network is preparing to air all 25 seasons (and the movie) of one of the greatest television shows of all time from August 21st to September 1st. In addition, Variety reports that FXX will launch the Simpsons World digital hub in October, which will allow cable subscribers to watch every episode on demand on their desktops at SimpsonsWorld.com, mobile devices via the FXNow app, and on compatible smart TVs and set-top boxes.