What is a GM pk3?

A GM PK3 refers to a type of file format used in Video Games, particularly in the context of the Doom engine and its derivatives. The "PK3" extension stands for "pack 3," indicating that it is a compressed archive file that typically contains game assets such as textures, sounds, and levels. These files are often used in modding communities to share custom content or modifications for games that utilize the Doom engine.