Keep up-to-date - Visit uniCenta oPOS Community News http://sourceforge.net/projects/unicentaopos/news/
uniCenta oPOS is a multi-lingual POS (Point-Of-Sale) application designed for Touchscreens. It supports industry standard hardware and is capable of running on display sizes from as little as 800x600 upwards.
Installing uniCenta oPOS is simple and fast and it comes packaged with its own built in Apache Derby Embedded database. It's also multi-terminal, multi-location and supports a range of proven commercial grade databases such as Apache Derby Client/Server, MySQL, HSQLDB, PostgreSQL and Oracle 11g.
It has a thriving and active self-serve Community here on Sourceforge.
Source code can be downloaded from http://www.unicenta.com/downloads