I love it also. The XML ecosystem is truly staggering. I can't say if any of it is "because" of XML, or simply XML was the thing these different projects hitch

I love it also. The XML ecosystem is truly staggering. I can't say if any of it is "because" of XML, or simply XML was the thing these different projects hitched their wagons too, just because of ubiquity and momentum. It is imperfect, but still extraordinary. One of my favorites is XSL/XLT. Yes it's a programming language in XML that's apt at working with XML. But that's the thing, you have an XML programming language that can easily manipulate XML. What other language does that remind folks of? It's also functional. Hard to hear yourself think around XSL because of all the buzzwords flying around. An early idea, which never caught on, but was still clever, was download XSL files to the client, and then simply serving up XML files to be rendered by the local XSL. We actually did this with CDAs in healthcare (CDAs are essentially XML health care records). That was a driving thing with CDAs. There were actually contests for student groups to come up with stylings of CDAs. The idea of stylesheets and XML is really powerful. HTML and CSS are joined at the hip, but that's happenstance. CSS can be applied to raw XML, but that aspect of it never matured like HTML and CSS did. Then you have things like XSL-FO, giving a straight pipeline from raw XML to a formatted output. I love XML namespaces. The idea of "hiding" meta data into XML files is quite cool. It was straight forward to consider XML elements in other name spaces as no more interesting than comments. This was used to great effect in SOAP and web services. A nice use case was bundling XML-Sig payloads. This was used in SOAP, in SAML. That was the beauty of it. In theory, you could plonk it most anywhere. Yes, it had its problems regarding normalization and such. And, yes, XML is complicated. There were certainly some sharp corners in dark rooms to bang you head on with XML. It suffered interoperability issues, but then everything did. Everything still does. That's not XMLs fault, that's just humanity. It's a powerful lingua franca. Once you get something into an XML format, there's so much that can be done with it, stuff we've been doing for 20 years. JSON et al are still trying to catch up, and suffering similar problems that XML has suffered through.