If you need to convert files from one markup format into another, pandoc is your swiss-army knife. Need to generate a man page from a markdown file? No problem. LaTeX to Docbook? Sure. HTML to MediaWiki? Yes, that too. Pandoc can read markdown and (subsets of) reStructuredText, textile, HTML, and LaTeX, and it can write plain text, markdown, reStructuredText, HTML, LaTeX, ConTeXt, PDF, RTF, DocBook XML, OpenDocument XML, ODT, GNU Texinfo, MediaWiki markup, textile, groff man pages, Emacs org-mode, EPUB ebooks, and S5 and Slidy HTML slide shows. PDF output (via LaTeX) is also supported with the included markdown2pdf wrapper script.
Pandoc is in the MacPorts, Debian, Ubuntu, Slackware, Arch, Fedora, NetBSD, and FreeBSD ports repositories. There is also a Windows installer.
Pandoc is free software, released under the GPL.
Website http://johnmacfarlane.net/pandoc/index.htmlMarkdown is a text-to-HTML conversion tool for web writers. 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.
So you could maintain one text file, for say documentation, and then generate various formats from the same source, html, wiki etc.
Edit: Doing some more research on this and found some similar tools for document creation.