YAML was my first thought as well. Why not a library that converts back and forth and displayed the YAML in a pre tag or textarea? Then you could edit the YAML and after converting back still have valid JSON.
YAML is a superset of JSON, but as long as the YAML used to convert to JSON started as JSON, there shouldn't be a problem.
YAML is a superset of JSON, but as long as the YAML used to convert to JSON started as JSON, there shouldn't be a problem.