AFT (Almost Free Text) is a document preparation system. It is mostly
free form meaning that there is little intrusive markup. AFT source
documents look a lot like plain old ASCII text.

AFT has a few rules for structuring your document and these rules have
more to do with formatting your text rather than embedding commands.

Right now, AFT produces pretty good (weblint-able) HTML, XHTML, LaTeX,
lout and RTF. It can, in fact, be coerced into producing all types of
output (e.g. roll-your-own XML). All that needs to be done is to edit
a rule file. You can even customize your own HTML rule files for
specialized output.

WWW: http://www.maplefish.com/todd/aft.html