Topic update:
MultiMarkdown v6.5.1 released 2019-12-29 (changelog and downloads at
https://github.com/fletcher/MultiMarkdown-6/releases).
MultiMarkdown adds these features to the basic Markdown syntax: footnotes, tables, citations and bibliography (works best in LaTeX using BibTeX), math support, automatic cross-referencing ability, smart typography, support for multiple languages, image attributes, table and image captions, definition lists, glossary entries (LaTeX only), document metadata (e.g. title, author, etc.).
A single MultiMarkdown file can be easily converted by the MMD program into: HTML/XHTML, LaTeX (which can be processed into a PDF), OpenDocument Text document [ODT], OPML [outlines]. [...] By using MultiMarkdown to create an OpenDocument file, you can then use any good word processor to convert that OpenDocument into other formats: RTF, Microsoft Word, multiple other word-processor formats.
With a little forethought, a single plain text document can easily be converted into multiple output formats without having to rewrite the entire thing or format it by hand. Even better, you don't have to write in "computer-ese" to create well formatted HTML or LaTeX.