PHP Point Of Sale - Point of Sale software
uniCenta oPOS - Award winning Point Of Sale
Floreant POS - Floreant POS :: Open Source Point of Sale – Think POS Think Floreant
Openbravo POS - Openbravo POS is the leading open source Point-of-Sale (POS) application in the retail industry.
Chromis POS - Download Chromis POS for free.
Lightspeed - retail and restaurant point-of-sale, ecommerce, and omnichannel solution