sm64coopdx

What you need: An unmodified ROM of Super Mario 64, US version, in .z64 format, dumped from your own cartridge.

sm64coopdx, short for Super Mario 64 Coop Deluxe, is a native PC port of Super Mario 64 built from the game’s decompilation, focused on online multiplayer.

Up to 16 players can explore the game together, each as their own character, with Lua mod support, custom characters, levels and game modes.

The download contains no Nintendo data. It asks for a ROM of the US version of the game, dumped from your own copy.

How to set it up

1. Extract the whole archive to a folder you can write to.
2. Run the program in the extracted folder.
3. On first launch it shows “No rom detected”: drag and drop your US .z64 ROM onto the window. It is checked and copied, so you only do this once.