GW is the onboard artificial intelligence system in Metal Gear Solid 2: Sons of Liberty that controls Arsenal Gear. Its full designation is the Arsenal Gear AI, and it is central to the game's explanation of the Patriots' information-control system.
GW is housed within Arsenal Gear and processes enormous quantities of digital information. The AI's apparent breakdown and the strange messages received by Raiden are used to reveal how the Patriots manipulate data, perception, and communication.
GW is easy to confuse with other AI names in the wider series. JD is a higher-level Patriots AI introduced in Metal Gear Solid 4, while SOP refers to the Sons of the Patriots system. Peace Walker is an AI weapon and platform from a different game, not Arsenal Gear's controlling intelligence.