title: What does "headless" mean?
body: <p>While reading the <a href="http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/QTKitApplicationProgrammingGuide/AnatomyoftheQTKFramework/AnatomyoftheQTKFramework.html" rel="noreferrer">QTKit Application Programming Guide</a> I came across the term 'headless environments' - what does this mean? Here is the passage:</p>
  
  <blockquote>
    <p>...including applications with a GUI and tools intended to run in a “headless” environment. For example, you can use the framework to write command-line tools that manipulate QuickTime movie files.</p>
  </blockquote>