SAPdb (http://www.sapdb.org/) is a relational database which is performance- and scalabilitywise comparable to Oracle and Informix (it's a branch off Adabas D, look at http://www.sapdb.org/framesets/sap_db_features.htm).
That's OK so far, but this one is _free_, and in the process of becoming open source. I just lately stumbled across it, by coincidence, am not associated wit them whatsoever, just thought you might be interested, and as glad as I was to know there's a big, full-featured db for free (DBI interface supported). If you already know about that one, I'm sorry. I didn't find it mentioned anywhere, not mailinglists, readmes, driver collections etc. but thought it deserves to be there. greetings, jo (I hope this'll get through although I'm not on the mailing list)
