Linux Canada Inc
- Offer a point of sale application called 'Quasar'.
- http://www.linuxcanada.com/pos.shtml

Free Linux Point of Sale
- A complete point of sale system including a dedicated back office server, and web based administration interfaces.
- http://www.bananahead.com/

easyPOS;
- easyPOS is a GPL cash register written in C using GTK+.
- http://easypos.sourceforge.net/

gShop
- The gShop Project is an OpenSource Project to create a fully-featured retail point of sale application, suitable for a range of businesses.
- http://gshop.sourceforge.net/

DNA Lounge: Source Code: Point-of-Sale
- Point-of-Sale demo code at DNA Lounge.
- http://www.dnalounge.com/backstage/src/pos/

Linux Point Of Sale Software & Equipment
- Touchscreen POS for restaurants and food & beverage organizations. Point Of Sale for resale for Linux and BSD.
- http://www.viewtouch.com/poshome.html