RD (Ruby Document) is a lightweight markup language for writing Ruby-related documents. It can be embedded in Ruby source code.
Contents
RD is a traditional format. In modern Ruby, developers tend to write documents in RDoc instead of RD.
Use
RD was used for many documentation in the Ruby world. The documentation for Ruby itself was originally written in RD. In 2002, the documentation was re-written in RDoc format. The Japanese version of the Ruby Reference Manual is still written in RD.
RD is easy to read in the raw. It is designed to read or write by hand. But, in most cases, end-users read it after it has been converted into man pages or HTML pages.
Pure RD files usually have the extension .rd. RD can be embedded in Ruby code.
Sample RD document
This document is syntactically correct RD, which attempts to follow the major conventions on section naming as well.