Hello!
We've just released a small business management package for linux and windows that uses postgres as its database.
From the web site:
Callisto brings the power and convenience of data-based business management to small companies.
Callisto allows your company to track customers, enter orders and keep your books. The information you need to make smart decisions is at your finger tips. Connect to your data from other ODBC based software, like Excel and Word, and have full control over how your data is presented and analyzed. Callisto even lets you connect to your data from anywhere in the world, without changing how you enter information.
http://www.redrocketconsortium.com/Callisto/index.html
Yours,
Matthew Goodwin