also i've been working on a markdown replacement. simpler syntax, much more capable, ref impl is written in lua (no external dependencies beyond the interpreter tho), has an actual (if still very rough) spec, very compact and extensible, comes with freedesktop integration (double-click on a *.ct file and it'll render and open in your browser). it generates pages like the attached and the page generator is very configurable (accent colors, light-on-dark, page width, etc)
it's nowhere near finished (i'm planning to add at least groff support in addition to html, so it can be used to make pdfs, ideally also postscript), but it's already pretty usable as-is. has most of markdown's features (except blockquotes, working on those) and many more besides. i'll probably have the spec fully implemented in a few days
i'm writing this primarily for my own use, to replace the godawful perl script with its hand-implemented markdown-oid that i currently use to render story chapters for
http://ʞ.cc but if anyone else is interested, i hope i'll be more broadly useful as well. and suggestions
https://c.hale.su/cortav