@lanodan @kaia @chjara I don't see the problem with s-exp for XML, it can convey the same information far more expressively.
e.g.: https://en.wikipedia.org/wiki/MathML#Content_MathML
The C shenanigans & debt can be minimized with a mild performance tradeoff from the right abstractions.
The real solution would be to get rid of the C base though.
By all means no new C software should be written save for that needed to help with its deprecation.