uniCenta oPOS - Award winning Point Of Sale
Grisbi - Accounting for everyone !
Floreant POS - Floreant POS :: Open Source Point of Sale – Think POS Think Floreant
Ledger-cli.org - Ledger is a powerful, double-entry accounting system that is accessed from the UNIX command-line.
ERPLY - ERPLY.com is a web based affordable point of sale software and inventory system.
Gnuaccounting - Gnuaccounting is a Free Java cross-platform accounting and bookkeeping application. Features