eHopper POS - The eHopper POS system is developed with small businesses in mind.
SellerCloud - SellerCloud is a multi-channel inventory and order management system.
Lightspeed - retail and restaurant point-of-sale, ecommerce, and omnichannel solution
Sellbrite - Multichannel ecommerce management for serious sellers.
Floreant POS - Floreant POS :: Open Source Point of Sale – Think POS Think Floreant
Webgility - Accounting, Bookkeeping and Inventory Automation for Retailers & Brands