It is recommended to use a clean (fresh) Debian lenny install where you just selected "Standard System" as the package selection during setup. Then follow the steps below to setup your server with ISPConfig 3. In this guide "vi" is used as texteditor, but you ofcourse you can use whatever you prefer.
Markdown is a text-to-HTML conversion tool for web writers written by John Gruber. Markdown allows you to write using an easy-to-read, easy-to-write plain text format, then convert it to structurally valid XHTML (or HTML).
Thus, Markdown is two things: (1) a plain text formatting syntax; and (2) a software tool, written in Perl, that converts the plain text formatting to HTML. See the Syntax page for details pertaining to Markdown’s formatting syntax.