The hugely popular php/mysql shopping cart from prestashop is now available in cloud form. So no need to download and host the shopping cart yourself. Start an online store in minutes for free including hosting.
So how do they make money? Prestashop run a large module and themes marketplace and sales from this market place go partly to Prestashop and the rest to the developer. The download version allows you to see the source code and modify it yourself also you can access the database. But the hosted version restricts you from doing this. So is this the shopify killer?