CultPOS is a "Point of Sale" system designed to work with touchscreens. The frontend for making orders (TouchGUI) is written in platform independent C++/Qt, the backend for managing products and accounting (DbGUI) are scripts for OpenOffice
QNewsletterCreator is a program to manage your newsletters and recipients thereof. Since it is written with Qt, it is platform independent. The newsletter can consist of both html or plain-text and have attachments as well.