Marvel comics continuity
Bludgeon's purpose for creating the Warworld was as a ship for stealing energy and other resources throughout space (including those from the Jabbi-Ko, Karkan, and Szorian races). It was originally his flagship and host to his army of Decepticon clones.
When Megatron battled and destroyed Bludgeon, he took command of the crew and ship. The Warworld was involved in many Autobot conflicts.
Starscream stole the Matrix and used its power to combine himself with the Warworld. He reshaped its interior, battled Jhiaxus's troops, and tortured Megatron and Optimus Prime. But the Matrix's essence started to turn him from his evil ways. Starscream was so scared of becoming good that he did not put up any resistance when Optimus Prime and Megatron took the Matrix away from him.
Note: The general look of the Warworld tended to change as the series progressed. In-fiction, this could be the result of its nature as a continuously-growing patchwork of stolen alien technology. In reality, it's what you get when three very different artists depict a massive glob of sprawling machinery.
Japanese Generation 2
- Another spherical super-weapon also called War World appeared in the Superman comics.