[Frozenlock]

You could look at Org Mode. You can write your document in a similar fashion you would with Markdown, but then you can export in many other formats (including exporting to LaTeX and PdfTeX).

[srik]

Isn't Org Mode tied to one editor.

[melling]

Don't think so. It's simply a file format like markdown. Github will render org files. Think they use this Ruby gem.

https://github.com/bdewey/org-ruby

Perhaps we need more complete implementations but there's nothing preventing anyone from finishing the job.