The standard way configuration data is kept in unices is by various different config files under the /etc directory.
This mix of different textformats is unlikely to change given various pros and cons.
With the config4gnu config representation and manipulation framework in debian however the cons can be eliminated and new possibilities arise.
Full flexibility and authority of /etc is maintainted. Flexibility is even increased, a API and several frondends (comandline, GUI etc.) to all config files and formats are provided without hardcoded specifics!
Meta-config definitions do the trick.
Check out the webpage: http://freedesktop.org/Software/CFG
"Points of Integration config4gnu in debian" (or better integrate debian into config4gnu ?):