[adiM]

I often wonder, if one is going to add such tags anyways, why not directly use LaTeX, ConTeXt, XML, ... for example

\begin{conccurrent}{Hacker News Thread} I'm writing in an HN thread. \end{concurrent}

is not so different from the markdown source. All the benefits you mention are simply from using semantic markup.

[bombcar]

I understand the desire to use Markdown - if you’re not using an editor that will dump the “begin/end” for you with a keystroke or two it feels faster.

[o11c]

The problem with TeX is that it's a write-only imperative language. Good luck performing meaningful operations on the data.

XML, for all its human-unfriendliness, is very good for declarative document layout that you can later feed into some random process.

[adiM]

I use ConTeXt, and it is relatively simple to get each environment to whatever you want (plus you can code everything in Lua).