Torg was a roleplaying game released about thirty years ago in which earth was invaded by different realities, different genres of roleplaying game, and you played characters from these different realities who all worked together to fight the invaders. Thus, fantasy wizards worked with cyberpunk hackers and two-fisted pulp detectives to defeat dinosaur-riding lizardmen. It was a lot of fun, but never one that I got into in any depth.
A couple of years ago it was relaunched as Torg Eternity, with new rules and a slightly revised background. The publisher also created a Community Content program, the Infiniverse Exchange, where fans of the game can publish material for it and charge money for them.