I'd add that another advantage of XML is that you get a powerful set of tools that are readily accessible across all "working" programming languages, often provided by first party libraries. Plus a lot of developers (and text editors) know the basic syntax.
Granted, JSON has achieved this same level of universality, but everything else (excepting perhaps CSV files) either suffers from obscurity or from weak/ambiguous/competing specifications.
The dream of semantically rich documents that XML provides (like, say, being able to cleanly interweave MathML, SVG, and XHTML in one document) is unmatched.
I think we'd see a lot more XML usage if it hasn't been over-promised, over-delivered (WS-*), and over-used (enterprise Java). If XML had stuck to its lane (making a schema language like RelaxNG instead of XmlSchema, for one thing) it wouldn't have left such a bad taste in so many people's mouths.
Granted, JSON has achieved this same level of universality, but everything else (excepting perhaps CSV files) either suffers from obscurity or from weak/ambiguous/competing specifications.
The dream of semantically rich documents that XML provides (like, say, being able to cleanly interweave MathML, SVG, and XHTML in one document) is unmatched.
I think we'd see a lot more XML usage if it hasn't been over-promised, over-delivered (WS-*), and over-used (enterprise Java). If XML had stuck to its lane (making a schema language like RelaxNG instead of XmlSchema, for one thing) it wouldn't have left such a bad taste in so many people's mouths.