JSON is a lot friendlier up front though, and hopefully you don't need to go all-in. But the rabbit hole can get pretty deep with both JSON and XML validation,

JSON is a lot friendlier up front though, and hopefully you don't need to go all-in. But the rabbit hole can get pretty deep with both JSON and XML validation, meta-schemas and -DTDs. Depending on what you're trying to do, some of the newer approaches like Cue might fit the bill better or at least feel less like a convoluted mess.