What are some alternatives?
When comparing Challenger POS & Restaurant and POSper, you can also consider the following products
uniCenta oPOS - Award winning Point Of Sale
KORONA.pos Cloud - KORONA.
Gazelle Point-of-Sale - Gazelle Point-of-Sale is a cloud web-based POS and inventory software. We have native iPad app, native Android app and offline support. Free POS desktop version available.
Abacre Restaurant Point of Sale - A complete restaurant management system that encompasses all aspects of the restaurant, from taking orders to billing and tax reports.
PHP Point Of Sale - Point of Sale software
Floreant POS - Floreant POS :: Open Source Point of Sale – Think POS Think Floreant