Opensource Object Database?

Question

Is there any open source Object Database available? I would like to have a look at the source code and see how stuffs are implemented.

Answer 1

http://www.zope.org/Wikis/ZODB is the first coming to mind, but here's a list of both commercial and open source object databases:

http://www.odbms.org/vendors.html

Answer 2

Prevayler is one of them.

Answer 3

CouchDB is a document database, much the same thing as an object one.

Answer 4

db4o is my favorite.

Answer 5

You probably want to take a look at Magma, a Smalltalk OODB inspired by Gemstone.

Magma is an OODB with full source in Squeak Smalltalk. See http://wiki.squeak.org/squeak/2665. Even if you want to use a different implementation language, reading the code should be helpful. There is an active mailing list, where questions are answered quickly.

Gemstone is probably the largest OODB company, with the best track-record. It used to be very expensive, but they introduced a free but not open source version for small (4GB) databases recently in their GLASS (Gemstone, Linux, Apache and Seaside) offering.