Hey, today is XML’s 25th birthday. Back in the day I wrote a lot about it: https://www.tbray.org/ongoing/What/Technology/XML/
Probably the most important: Neither XML’s father nor inventor: https://www.tbray.org/ongoing/When/200x/2008/11/22/Not-the-Inventor-of-XML
Amusing: “XML People”: https://www.tbray.org/ongoing/When/200x/2008/02/10/XML-People
Quoting from “What XML Means” (2007): “XML is the first successful instance of a data packaging system that is simultaneously (human) language-independent and (computer) system-independent. It’s the existence proof that such a thing can be built and be useful.”