I Looked at the site for z.m.l (http://www.z-m-l.com/). It doesn't seem to do math, so it's a nonstarter.

BTW, Pandoc (which does do LaTeX math) really needs no improvement, only more widespread implementation (e.g., an online site, and/or a chrome extension coded in javascript.) I suppose its being written in Haskell has been an impediment.