Ever since the first arcade games appeared, gamers have tried to leave their own mark on their favorite titles. Back then, you left a cool, perhaps offensive, set of initials in the machine's high-score column.
Over time, software companies have tried to key into this desire by giving gamers an increasingly impressive set of tools to personalize their games. But now, gaming companies - aided by hardware advances, online networks and the proliferation of broadband - are equipping players with an unprecedented amount of creative power to, in essence, design their own games and share them online with others.
Gamers, who were once enticed by the fantasy of becoming heroes, sports stars and warriors, are now being invited to become game developers.