Help writing backend or overlay?

[Michael.Smith@domino1.cuny.edu]

Can anyone point me to resources that would be helpful 
in writing a custom backend or overlay? For example, documentation 
of the backend and overlay APIs and the relevant OpenLDAP 
data structures? I've done the obvious googling and come up with 
very little. 

Best of all, of course, would be A Big Dummy's Guide To Overlays 
And Backends. -- Well, a guy can dream, can't he? 

Thanks in advance -- 

--Michael J. Smith
--michael.smith@mail.cuny.edu