First, let’s decouple the jargon. Super Smash Bros. Melee was released in three major regional revisions (often called "dolphin" versions based on the code on the disc):
This is a crucial topic. Emulators like Dolphin are completely legal; they are simply software that recreates the functionality of the GameCube.
For the modern competitive experience, follow these steps to use your ISO on PC: Download Slippi: