Showdown's a great library, I use it with some tweaks on http://notepag.es/ http://notepag.es/ for doing markdown/latex math editing. Given it is just a chain o

Showdown's a great library, I use it with some tweaks on http://notepag.es/ http://notepag.es/ for doing markdown/latex math editing. Given it is just a chain of regexes though, modifying it to add new functionality can be a little hairy.