You don't have to tell the crew of people painstakingly piecing together Mario Kart: Source that there's a much easier way to play Mario Kart games on PCs. Sure, they could fire up an emulator and play Mario Kart 64 and it would be just like it was way back when ... but where's the challenge in that? What they could (and did) opt to do was take Half-Life 2's flexible Source Engine to create a Mario Kart mashup; the project manager says, "We're not simply recreating one version of MK, but using the best parts of each." It's a Franken-kart, if you will.
Eager to get a closer look at it? Peep the gallery we quickly threw together, or dig around the project's official site. Want to actually play the thing? Says the project manager: "As far as a public beta is concerned, we will not release anything until we are satisfied ..." Either that, or until Nintendo's army of well-paid lawyers shuts the entire project down.