- Browsers are XSLT (1.0) processors.

- Xee: https://github.com/Paligo/xee

- xrust: https://docs.rs/xrust/latest/xrust/xslt/

- XJSLT (compiles XSLT to JS): https://github.com/egh/xjslt

Xee is WIP AFAIK and I don't know the maturity of xrust and XJSLT.

I only know libxslt, but it's XSLT 1.0 and some of EXSLT. I don't recommend.