Interesting that nobody pointed out the tooling dimension of XML's demise yet. (edit: actually there was another comment too: https://news.ycombinator.com/item?

Interesting that nobody pointed out the tooling dimension of XML's demise yet. (edit: actually there was another comment too: https://news.ycombinator.com/item?id=24623696 https://news.ycombinator.com/item?id=24623696) You really need a high level of support in editors and other tools to make it good for humans to work with, to just showing the AST and to hide the unusably verbose surface syntax. This support didn't materialize widely enough for whatever reason. Of course you can say that it's just a convoluted way of saying the syntax wasn't good enough - but at the time the argument was that tooling will be good enougg and will solve the issue. So it's still a good lesson about tooling.