My friend David Young used to be president of Lutris (company that created Enhydra originally) and Lutris' CTO Paul Morgan hired me as a consultant to add web services support to their commercial version of Enhydra several years ago. I don't believe that Lutris is still in business, but fortunately Enhydra is now supported by the European ObjectWeb organization (they provide a lot of high quality software - check them out if you have not already done so).

Enhydra is available here.