TeXMe Demo: Self-Rendering Markdown and MathJax Documents

I find that the experience of writing (La)TeX depends a lot on what you are using to write it. For me, Emacs' AuC-TeX [1] is nearly perfect: it has shortcuts and autocompletion for almost all the environment names and commands, inline preview, BibTeX searches (via RefTeX), and a number of other minor features that make it easy to write LaTeX. Honestly, I wish that other text-writing modes (like markdown-mode) would implement the interface and functionality of AuC-TeX and not the other way round.

As for the syntax: I love Markdown for writing very simple text content, but as soon as you need to do something just a little more complicated it becomes awkward (e.g., table entries that span multiple paragraphs) and some task are simply impossible (e.g. referencing a list item by label value, the way you do it with TeX's `\label` and `\ref`). The programmability of TeX-based systems is actually a great thing that lets you write shorter documents and push many aesthetics decisions to a `.sty` file (e.g., you can at any time change your mind on how `\vector{u}` should be rendered).

[1]: https://www.gnu.org/software/auctex/

The closest thing I can think of would be AsciiDoc. Though not made specifically for pdf you can render it to anything with relative ease, though the same could be said for markdown itself.