Tim Bray, co-editor of the XML spec, writing in 2006 on the topic:
> Use JSON: Seems easy to me; if you want to serialize a data structure that’s not too text-heavy and all you want is for the receiver to get the same data structure with minimal effort, and you trust the other end to get the i18n right, JSON is hunky-dory.
> Use XML: If you want to provide general-purpose data that the receiver might want to do unforeseen weird and crazy things with, or if you want to be really paranoid and picky about i18n, or if what you’re sending is more like a document than a struct, or if the order of the data matters, or if the data is potentially long-lived (as in, more than seconds) XML is the way to go.
Tim Bray, co-editor of the XML spec, writing in 2006 on the topic:
> Use JSON: Seems easy to me; if you want to serialize a data structure that’s not too text-heavy and all you want is for the receiver to get the same data structure with minimal effort, and you trust the other end to get the i18n right, JSON is hunky-dory.
> Use XML: If you want to provide general-purpose data that the receiver might want to do unforeseen weird and crazy things with, or if you want to be really paranoid and picky about i18n, or if what you’re sending is more like a document than a struct, or if the order of the data matters, or if the data is potentially long-lived (as in, more than seconds) XML is the way to go.
* https://www.tbray.org/ongoing/When/200x/2006/12/21/JSON
He was also editor of the JSON RFCs:
* https://tools.ietf.org/html/rfc7159
* https://tools.ietf.org/html/rfc8259