The .gcm extension is an image file format for a Nintendo GameCube game disc, often used with emulators like Dolphin. In the case of exp-n64v2.gcm , this specific image contains a modified version of an official N64 emulator created by Nintendo for its GameCube compilation disc, The Legend of Zelda: Collector's Edition . A group of developers known as extracted this emulator and made it available for hobbyist use.
To understand how the framework functions, it must be broken down into its three core structural pillars: expn64v2gcm work