title: What does open source license (like GNU-GPL) mean?
body: <p>I am looking forward to use an open source product which has GNU-GPL like license and it says that if I use that product, I must share the source code of my application.</p>
  
  <p>I am slightly confused about it. I understand that Linux is available under GNU-GPL license as well. Does it mean <strong>ALL</strong> linux application are and has to be open source? Does it mean I can ask for the source code of complete <strong>Oracle DB</strong> from Oracle Corp (at least the part that runs on Linux)?</p>
  
  <p>EDIT:</p>
  
  <p>Taken from <a href="http://www.gnu.org/licenses/gpl-faq.html#IfLibraryIsGPL" rel="noreferrer">FAQ</a>:</p>
  
  <blockquote>
    <p><strong>If a library is released under the GPL (not the LGPL), does that mean
    that any program which uses it has to
    be under the GPL or a GPL-compatible
    license?</strong></p>
    
    <p>Yes, because the program as it is
    actually run includes the library.</p>
  </blockquote>