YAML is easy to type, even with the whitespace. So is INI. And as verbose as XML is, it's easier, ime, to type than JSON. Of those four, JSON is the hardest to write by hand; certainly it's the one I make most mistakes with, to extent I have a particular technique for writing it out (prefixing the commas). As a result JSON as a config file format is tedious, verbose, and error prone; its sweet spot is a machine interchange format that a human can debug/read if needed.
YAML is easy to type, even with the whitespace. So is INI. And as verbose as XML is, it's easier, ime, to type than JSON. Of those four, JSON is the hardest to write by hand; certainly it's the one I make most mistakes with, to extent I have a particular technique for writing it out (prefixing the commas). As a result JSON as a config file format is tedious, verbose, and error prone; its sweet spot is a machine interchange format that a human can debug/read if needed.