Apple took a slightly different approach
Plain text config files are kept for backward compatibility, but where possible OS X uses *.plist files to store configuration information. These are still plain text for the most part, but use XML.
I say 'for the most part' since they started out as text files, some of them are now binary, a move which I view with some paranoia.
Tom Sinclair
"This is a lovely party," said the Bursar to a chair, "I wish I was here."
-- The Bursar is a man under a *lot* of stress
(Terry Pratchett, Lords and Ladies)