What I posted is valid XML. And even prettified, it's a pain to read.

it was valid but not the way XML is written or read by humans which is what we are discussing. how much of a pain it is to read is a matter of taste. i won't deny that. but XML can be made more readable without fail because it is a structured format. i would not have been ale to reformat a patch text the way i reformatted this XML example. XML is also more powerful. it could handle word based changes, as opposed to patch which can only do line based changes. same goes for JSON. patch could potentially be improved, but i don't see how it could handle word based changes without extra syntax to mark line breaks.