A simple script that takes a template, markdown file, and an optional foreword and spits out an HTML file.

md2html.rb

#!/usr/bin/env ruby

require 'liquid'
require 'redcarpet'

if ARGV.length < 2
  puts "Usage: md2html <template> <markdown_doc> [markdown_foreword]"
  exit
end

template = File.read(ARGV[0])
document = File.read(ARGV[1])
preamble = File.read(ARGV[2]) if ARGV.length > 2

renderer = Redcarpet::Render::HTML.new(:with_toc_data => true)
markdown = Redcarpet::Markdown.new(renderer, :autolink => true, :space_after_headers => true, :tables => true)
tocgen = Redcarpet::Markdown.new(Redcarpet::Render::HTML_TOC)

preamble = markdown.render(preamble) if preamble
contents = markdown.render(document)
toc = tocgen.render(document)

print Liquid::Template.parse(template).render('content' => contents,
                                              'toc' => toc,
                                              'preamble' => preamble,
                                              'title' => "Philotomy's Musings")

This is currently used to generate this page: Philotomy's Musings and a few other simple pages.