[dstein]

The XML is better because when the data types directly relate to tag names it is simple to understand, read, and write, process, and there are tons of XML libraries in every language that do object-xml serialization automatically. With JSON, since there are no types, you must manually write your own data-object serialization and embed the type system right into the data structure itself.

[j_baker]

It sounds like that might be better for a statically-typed language where you might need specific types in the data file. But I would argue that not only is it overkill in a dynamically-typed language, it's bad. We're talking about data here. There's no reason to couple it to data types in your code.

Plus, serialization to JSON in a dynamically-typed language is pretty much automagic compared to what you have to do with XML.