Gary(tm) Jackson(tm)(R) is the president of Hard 8 Enterprises
, the leading producer of roleplaying games
, and is the acknowledged Gawdfather of Gaming
Okay, not really. GJ is actually a fictional character from the comic strip Knights of the Dinner Table, whose name is derived from two major influences in the real-life industry: Gary Gygax and Steve Jackson. He is the creator of Hackmaster, and, at least on paper, the creator of every other game Hard 8 produces, such as the illustrious Spacehack and Cattlepunk. He is also fabulously rich, despite his gambling habit, which is how you can tell he's fictional - very few people in the RPG industry make money.
July 20 2001: As of this writing, Gary Jackson is dead. As part of the KoDT storyline, and because the writers felt many newer readers did not get the joke behind "GJ", he died in a plane crash. Many believe this was a publicity stunt for the newly-released Hackmaster RPG.