in a good company
Before announcing QaTeX, Jonathan Fine sent an advance notice to several persons.
* me, sTeXme
* Scott Pakin, PerlTeX
* Dorai Sitaram, eval4TEX (part of TEX2page)
* Francois Pinard), Pymacs
I'd like to highlight:
QaTeX. The approach is quite simple, but very powerful.
The EuroTeX 2005 paper with covers all the projects above and more.
TEX2page. I haven't used it, but it seems it's one of the best parsers and interpreters of the TeX syntax.