This doesn't make sense. JSON is used because it's a handy data interchange format, but it doesn't mean it's the best tool for every job. XML is a document markup language that is much, much better than JSON for describing interfaces and alike. And even then it's not really ideal for describing control flow and computations that are needed for any meaningful app that is not a static page (see XAML, AngularJS, FXML, - they do have some power but they're still tied to real programming languages: C#, Javascript, and Java, respectively.)

And all computers and devices made in the last century have no problem dealing with XML, HTML, JS over the wire - in fact this is exactly what web browsers have been doing. So even though you're dealing with native iOS apps and not webpages, that doesn't mean you can't use a similar XML format(or any other document markup language) along with a proper scripting language. And if you insist on staying close to JSON, you could go an all JS approach and use JS(instead of JSON) to describe your views, and also be able to embed JS computations - this is exactly what React does, and does very well.

And again, JSON is not a document markup language, so optimizing it for displaying documents/interfaces seems futile when you can just use XML and save yourself and the interpreter some pain.

> use a similar XML format(or any other document markup language) along with a proper scripting language

That's not simple. JSON is simple. Yours is two things, JSON is one thing. And a lot of people are responding positively to this, so the author may be on to something. JSON is NOT the best language for full expressiveness, you're absolutely right about that. But it's simple, it's one single syntax (not two), and it feels like "just configuration" even though you're doing the same amount of logic.

> so optimizing it for displaying documents/interfaces seems futile

I mean, this guy did it, didn't he? And it's open source so now you can too.

I'm glad people build new things. This is cool. Maybe it'll catch on, maybe it won't, but I'm glad he used JSON and not XML+JS. We already have phonegap and cocoon for that ;).

While you make some sense, you lost me the second you started talking about XML.

It's ugly as hell and always has been. I suspect only Java developers could love such a tedious, verbose thing ;-)

Everything that everyone ever told me had to be implemented in an XML flavor, I have implemented in JSON without trouble. This includes iOS and Android views and manifests, HTML (I choose jade/pug/haml), JSX (pug/hyperscript), AJAX (always gets parsed into native JS object). It's never been a problem for my career, and if enforced with strict formatting and whitespace, causes less errors due to closing tag, encoding, or nesting issues.

Plus, JSON is really close to YAML/coffeescript/Ruby/python/pug so I can write even less keystrokes and compile to JSON. I'd be really interested to see your interface implemented without the braces and brackets. I bet that would make it extremely approachable to non-programmers.