uniCenta

uniCenta oPOS is a free (no gotcha’s hidden away!) extremely flexible, robust, commercial-grade and business-ready touchscreen Electronic Point of Sale (EPoS) application.
Based on a proven, established open source solution it is localised for UK, Europe and USA (it’s easily re-configured for many other countries). It’s suitable for the Hospitality, Leisure & Retail markets and is a great solution for Bars and Cafes through to Restaurants and Supermarkets.

Could probably be what you’re looking for.

uniCenta oPOS - free Point of Sale