OpenCart - A free shopping cart system. OpenCart is an open source PHP-based online e-commerce solution.s
Perch - A bird’s eye view of social activity for you AND your competition.
WooCommerce - A freely available eCommerce plugin that enables shop facilities on your WordPress website. Functionality enabling extensions & beautiful themes available.
Double 2 - Giving you a physical presence when you can’t be there
PrestaShop - Create your online store with PrestaShop's free shopping cart software. Build an ecommerce website for free and start selling online with hundreds of powerful features.
Nudee - Create a 3D printed "nude selfie" (slightly NSFW)