I'm looking for a faithful implementation of ODMG 3.0 Standard for
OODBs that is available for free downloading and that would be suitable
for an introductory college course on OODBs. I've looked at several
ODMG-compliant products, but prefer to use a faithful and complete
implementation of ODMG 3.0 or its core subset thereof. Experimental implementations developed at universities or research labs, as long as they are reasonably robust and user-friendly, would be fine as well.

Any information would be much appreciated. Thanks.