uniCenta oPOS - Award winning Point Of Sale
POSper - POSper is a Point Of Sale (POS) System with touch screen support designed for small businesses.
ERPLY - ERPLY.com is a web based affordable point of sale software and inventory system.
Square for Retail - Point-of-sale app & set of tools for retail businesses
Floreant POS - Floreant POS :: Open Source Point of Sale – Think POS Think Floreant
Lightspeed - retail and restaurant point-of-sale, ecommerce, and omnichannel solution