XML isn't the most enjoyable thing to write (although we don't seem to have a problem when it comes to HTML and JSX). There's the whole debate around when to us

XML isn't the most enjoyable thing to write (although we don't seem to have a problem when it comes to HTML and JSX). There's the whole debate around when to use attributes or children, and all that, which I can see would be a problem if the schema is poorly defined. But then, it's not like YAML is any better with how confusing its whitespace rules can be, and all the short-hand ways of avoiding explicit syntax (see: do you indent arrays in a hash or not? What's up with having to double-indent in some cases but not another?). And given the length of many yaml-based configs, it becomes pretty much useless once you're a thousand lines in, which you'll easily approach with a CI config. At least with XML, you could actually attach a stylesheet to it (even just CSS) and you'd automatically have a human readable version of the file, without having to bother with converting YAML or JSON or whatever. That'd simplify the generation of a lot of internal dashboards.