XML has been "spooky old technology" for over a decade now. It's heyday was something like 2002.

Nobody dares advertise the XML capabilities of their product (which back then everybody did), nobody considers it either hot new thing (like back then) or mature - just obsolete enterprise shit.

It's about as popular now as J2EE, except to people that think "10 years ago" means 1999.

XML is still around, but I don't think many people would choose it as a serialization format today for something new.

XML is back, everyone is rediscovering the terminal. Soon we’ll discover that object oriented programming is good again.

If you think XML is old tech, wait until you hear of EDI, still powering Walmart and Amazon logistics. XML came in like a wrecking ball with its self-documenting promise designed to replace that cryptic pesky payload called EDI. XML promised to solve world hunger. It spawned SOAP, XML over RPC, DOM, DTD, the heyday was beautiful and Microsoft was leading the charge. C# was also right around this time. Consulting firms were bloomed charged with delivering the asynchronous revolution, the loosely coupled messaging promises of XML. I think it succeeded and it’s now quietly in the halls of warehouse having a beer or two with its older cousin the Electronic Data Interchange aka EDI.

XML is as old now as the PDP-11 was when XML came out.

I tried following the best practice to use XML tags and the difference was not observable. I honestly believe Anthropic forgot to remove that part of the documentation from Sonnet 3.x days and now people are still writing blogs about this secret sauce

XML works great for XMPP. KDL is compatible with it too.

What gets me is going from this structured data to Markdown which doesn’t even have enough features & syntax that the LLMs try to invent or co-opt things like the blockquote for not quoting sources.

It has a number of security issues which have not been fixed which could be used for really interesting exploitation.

The evidence suggests that XML was never that popular though for the general audience, you have to admit.

For Web markup, as an industry we tried XHTML (HTML that was strictly XML) for a while, and that didn't stick, and now we have HTML5 which is much more lenient as it doesn't even require closing tags in some cases.

For data exchange, people vastly prefer JSON as an exchange format for its simplicity, or protobuf and friends for their efficiency.

As a configuration format, it has been vastly overtaken by YAML, TOML, and INI, due to their content-forward syntax.

Having said all this I know there are some popular tools that use XML like ClickHouse, Apple's launchd, ROS, etc. but these are relatively niche compared to (e.g.) HTML

Yup. Kids these days...

[dead]