One of the things on my todo list for ZenMagick is to review the different types of config/option/setting formats used. Right now there are:

• plain PHP with static code
  This is handled via the loader and the most prominent special cases here are local.php files which are fine, though
• PHP code without the <?phph ?> tags
  Used for the database mappings – this should/could be nicer I guess, in particular since it might get cached as serialized array anyway
• list of method calls in a single global function
  Done for the sacs and url mappings. These could be a single array and perhaps should be. However, it would be nice to have a simple format that can easily be parsed

So, what do I want/need? .ini fileformat is too simple as there is some hierarchical data, although not too deep. Some nesting would be good too.

Of course, XML might be an idea, however I do not have any experience with XML and PHP and do not know what performance is like.

Any ideas?