open source
prestashop – http://www.prestashop.com/
zen cart – http://www.zen-cart.com/
os commerce – http://www.oscommerce.com/
pinnacle cart – http://www.pinnaclecart.com/
magneto- http://www.magentocommerce.com/
hosted
shopify – http://www.shopify.com/
volusion – http://www.volusion.com/
paid
cart keeper – http://www.cartkeeper.com/
wordpress carts
tribulant – www.tribulant.com
shop – https://shopplugin.net/
here is a reviewer for a selection of carts
http://www.shopping-cart-reviews.com/
