Frogcart - node.js shopping cart (opens in new tab)

Oh, and it's free for most users with 250 free carts per month. A cart is created the first time a user tries to add something to their cart, so for most people it'll either be free or pay for itself (only $0.05 per cart after 250)

The API layer is built in node.js https://api.frogcart.com/heartbeat

MVC 4 and Web API for the marketing and admin site. AWS load balancer, DNS and hosting.