Nothing to do with the way the AI works. The news suggests that once again modding will be done with XML. Is there any particular reason why YAML wouldn't have worked in its stead?
XML is great, making mods is really fast - merely 1 hour after the announcement was made, mods began to pop up... Though, Kazeto has a point: Edit: Kaidelong probably has a point too. 10:53 AM - Mining: That's how we should do merchant douchery, btw 10:53 AM - jcad: With dredmor script? Please god no
Both JSON and YAML are designed for serialization of objects. XML is designed for serialization of objects, too, but it handles objects-inside-objects-inside-objects very, very nicely. We could probably use any DSL, but at the point at which I switch from XML (which is, at least, a known quantity, and which we've all worked with) to another DSL, we lose experience and I'd rather just switch it to writing my own DSL. I don't want to write my own DSL and you don't want to use it. So XML it is! Yay.
My only complaint is that you're using angle brackets rather than square brackets. Those are precious seconds spent pressing shift that are better spent on grander things!
That is an extremely good point. I can't think of any good reason why anyone would use angle brackets over square brackets if given the choice.
Entry barrier is a one-off cost. Use is a running cost. Anyway TBH I'll probably be kept quite busy with other work. The one thing XML does have going for it is that it would be simple to "compile" something else into XML, but S-expressions, JSON et al. would work just fine for that anyway.
I'd just like to say, as a novice modder, you have my support on XML. Civilization, Crusader Kings 2, and Elemental have all done pretty well under XML. That being said, I don't know what DSL, YAML, JSON, and UNML even are. Whatever has the best functionality and understandability is probably the best choice. The more modding the merrier.