title: What are the differences and similarities between ffmpeg, libav, and avconv?
body: <p>When I run <code>ffmpeg</code> on Ubuntu, it shows:</p>
  
  <pre><code>$ ffmpeg 
  ffmpeg version v0.8, Copyright (c) 2000-2011 the Libav developers
    built on Feb 28 2012 13:27:36 with gcc 4.6.1
  This program is not developed anymore and is only provided for compatibility. Use avconv instead (see Changelog for the list of incompatible changes).
  </code></pre>
  
  <p>Or it shows (depending on the Ubuntu version):</p>
  
  <pre><code>$ ffmpeg
  ffmpeg version 0.8.5-6:0.8.5-0ubuntu0.12.10.1, Copyright (c) 2000-2012 the Libav developers
    built on Jan 24 2013 14:49:20 with gcc 4.7.2
  *** THIS PROGRAM IS DEPRECATED ***
  This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
  </code></pre>
  
  <p>I found avconv on <a href="http://libav.org" rel="noreferrer">http://libav.org</a>. I am just perplexed by them.</p>