Until the IGN article, I'd never heard of Project M

[Zeus]

It's a pretty extensive mod for Smash Brothers Brawl that the super-hardcores are making to "bring it more in line" with Melee. It works through the level editor of the game so there's no mods required (soft or hard) to your Wii at all. You just play the game , go to the level editior, and it works automatically. Currently only a demo available but it's got 29 of the planned 40 characters, so it's pretty damned extensive for a demo

http://projectm.dantarion.com/downloads/