It feels like a long term solution would be to use a markdown that is both easy to write (not RTF or XHTML), but has a defined grammar in some standard format (ex: EBNF). Most platform/languages will have a parser and so you can whip up a "renderer" or converter trivially at any point. The only markup I'm finding with a grammar is MediaWiki (sort of..) https://www.mediawiki.org/wiki/Markup_spec Even Djot doesn't seem…
"so you can whip up a "renderer" or converter trivially at any point" And yet almost no one has...
A simple grammar probably really limits how you can design your syntax.
Here is an example of the problems: