application.rb

require 'haml'
require 'sinatra/base'

class Application < Sinatra::Base
  configure do
    set :server, 'thin'
  end

  get '/' do
    haml :index
  end
end

config.ru

$LOAD_PATH.unshift(File.dirname(__FILE__))
require 'application'

run Application

Gemfile

source 'http://rubygems.org/'

gem 'sinatra', '~> 1.3.0'
gem 'thin'
gem 'haml'

index.haml

%h1 Index

layout.haml

!!!
%html
  %head
    %link{:rel => 'stylesheet', :type => 'text/css', :href => 'styles.css', :media => 'screen'}
    %title Φαρμακείο Metropolis 
  %body
    #wrapper
      #header
        #content
          = yield
      #footer
        %p Panagiotis Atmatzidis - All rights (c) reserved 2012