> XML is fundamentally incompatible with commonly used programming data structures, namely lists/arrays and structs/maps. Another way to say this is XML is a g

> XML is fundamentally incompatible with commonly used programming data structures, namely lists/arrays and structs/maps. Another way to say this is XML is a grammar formalism that deals purely with serialisation rather than higher-level structures that might be serialised such as co-inductive data structures. > While HTML technically is not XML, it's very close to it and XHTML still is a thing. XML and HTML-as-serialisation-format are both subsets of SGML.