(from the OSWorkflow documentation)

OSWorkflow is fairly different from most other workflow systems available, both commercially and in the open source world. What makes OSWorkflow different is that it is extremely flexible. This can be hard to grasp at first, however. For example, OSWorkflow does not mandate a graphical tool for developing workflows, and the recommended approach is to write the xml workflow descriptors 'by hand'. It is up to the application developer to provide this sort of integration, as well as any integration with existing code and databases. These may seem like problems to someone who is looking for a quick "plug-and-play" workflow solution, but we've found that such a solution never provides enough flexibility to properly fulfill all requirements in a full-blown application.