RDtool converts RD to HTML, man, etc.
RD is a multipurpose documentation format created for documentating
Ruby and output of Ruby world. Briefly, RD is to Ruby as POD is to
Perl.
Author: Tosh (Toshiro Kuwabara) <toshirok@yb3.so-net.ne.jp>
WWW: http://www2.pos.to/~tosh/ruby/rdtool/en/index.html