title: What is the most mature and maintained Markdown processor?
body: <p>I need to Process Markdown at the command line, so there is no real language restriction.</p>
  
  <p>Extra features such as pretty quotes and dashes are a welcome addition. Code blocks are a must, but they are part of the core I think.</p>
  
  <p>I want to output to HTML only, and I'm on a Unix environment.</p>