D★Mark is a language for marking up prose. It facilitates writing semantically meaningful text, without limiting itself to the semantics provided by HTML or Markdown.
If you’re a technical writer looking for a flexible markup language, D★Mark might be a good fit.
Here’s an example of D★Mark:
#para This a paragraph; an element in block form containing some text.
#note[only=web] This is a note that will %em{only} show up on web.
For details, see the D★Mark web page.