Zephyr Basecamp is a functioning GTK frontend and PostgreSQL backend enterprise project that gives small and midsize businesses the same level of inventory, order entry, sales tracking, and accounting functionality as would be expected from commercial applications. It has interfaces for both X11/GNOME/Linux and Windows.
Lazy8 Ledger is a very simple yet powerful accounting program designed for people who have experience in bookkeeping. It is a plugin for jEdit. You can enter any type of bookkeeping activity and break out the activities to any number of accounts. There are numerous standard reports that are the basis of accounting needs and then there are tools to make your own reports. Furthermore, it is Unicode-compatible in all respects.
In order to leave Windows behind most people need a fully-functional money management program. CheckBook Tracker seeks to solve that problem. It has the feel and features of packages like Microsoft Money without requiring the user to build their own sources or find an RPM for their distribution. Its features include Import / Export QIF files straight from Money or Quicken, autocomplete, check printing, split transactions, balance forecasts, online banking, and more.
AccWhizz is a multilingual accounting application for small business companies and accounting offices. It is modular, written in PHP 4.x, and operates on top of PHP GroupWare. It runs as a Web application with Apache and phpgroupware serving as a middle layer. Internal data is managed by PostgreSQL/MySQL databases. The SQL server can either be local or remote.
WebPBC (Project Budget Consolidator) is a Web-based application that enables small- to medium-sized companies to do budget consolidation on their projects. It is especially suitable for companies that coordinate projects that are geographically distributed. The Web-based interface allows managers, accountants, and organizers from anywhere in the world to access, update, and consolidate budget data stored on a central server.