To demonstrate the advantages of a database that supports navigation in time, I've developed the CompStrm Wiki. Anyone, once they login, can modify the contents of a Wiki. It is a bit like the Wild West sometimes, as pages can get renamed or deleted. Links can easily be broken and valuable content lost. That is because only the latest content can be accessed. The CompStrm Wiki can help. All content, once entered, remains accessible. Users can view all changes made to a page, and can even go back in time and navigate links to pages that no longer exist. (This applies to the topics list and page citations as well.) You can even create links on a Wiki page which specify the time at which a page is to be viewed. By adding the dimension of time, site management is made a lot easier. And for more dynamic subjects (e.g. documentation for a new project), users can now get a historical perspective. http://compstrm.sourceforge.net/wiki/index.html CompStrm builds on Twisted, using BSDDB as a transactional store. Bill la Forge