Is there a tool for converting cmark XML to HTML?

Is there a preexisting tool that converts output generated by cmark ... --to xml to HTML? I would like to make transformations to the AST in XML form and generate HTML from the resulting XML.

This could be done easily with an XSLT stylesheet.

Sure – I can think of lots of ways this could be done, and that’s why I explicitly asked about a preexisting tool.