In this directory (and sub directories), you can place your own builder definition xml's.

In mmbase.jar the 'core' builders are available, see:
jar:file:mmbase.jar!/org/mmbase/config/builder/INDEX 
These builders you must always have, and as long as mmbase.jar of the distro is present you cannot
not have them.

You can override them here though, if that for some reason is necessary.

Every other jar can contain it's own builder xml's in the same fashion.
