What backend ships with OpenLDAP as default?

[jrusoff@apple.com]

I've downloaded and built and tested the latest OpenLDAP package. I'm 
wondering what, if any, backend is part of the package that I downloaded 
from the OpenLDAP site? Are the tests merely creating records in memory? 
I couldn't find this in the faq. I'm working on adding in the Berkeley 
DB, and I'm wondering what DID I test earlier?
Thanks,
Jason Rusoff