Yes - it's called GF. It inputs HTML (or SNAFU, or GENERAL) documents,
and can output RTF, LaTeX or flat ASCII. It includes a style sheet
mechanism so you can control various aspects of the output. I haven't
used the RTF variation (not having anything that can print from RTF),
but going to LaTeX works quite nicely (module page-wide GIFs not being
handled properly if you go to two-column output).
<mike