IDK, the XML hysteria is similar by comparison to the dynamic and functional languages hysterias. And it pales in comparison to the micro services, SPA and the current AI hysterias.
https://en.wikipedia.org/wiki/XML_appliance
E.g.
https://www.serverwatch.com/hardware/power-up-xml-data-proce...
> An XML appliance is a special-purpose network device used to secure, manage and mediate XML traffic.
Holy moly