RedCloth is a module for using Textile in Ruby. Textile is a text
format. A very simple text format. Another stab at making readable text
that can be converted to HTML.

No need to use verbose HTML to build your docs, your blogs, your pages.
Textile gives you readable text while youre writing and beautiful text
for your readers. And if you need to break out into HTML, Textile will
allow you to do so.

WWW: http://www.whytheluckystiff.net/ruby/redcloth/