Mal's Ecommerce

One of the reasons I installed this cart is because the main site says it works with Mal's Ecommerce and PayPal.

I see nothing anywhere about Mal's other than on that page.

I see nothing anywhere about locating or uploading payment extensions that are not already installed.

What's the deal? Is Mal's available, and if so, where do I find it and how do I install / enable it?