[johncolanduoni]

I believe the spec is at XSLT 3.0 but no browser actually implemented past XSLT 1.0 (not 100% sure - almost nobody cared about this feature last month so hard to find good docs on support). HTML5 and C++ are cut from the same cloth - massive and no reference implementation so full of features that have been “standard” for 10 years but never implemented by anyone.

[notpushkin]

Yeah, sorry, the XSLT spec is at 3.0 right now of course, but the browsers don’t implement it, and the WHATWG HTML Living Standard only mentions XSLT 1.0.

[arccy]

even outside of browsers barely anything supports XSLT newer than 1.0