title: How to learn OpenGL 3.x using C?
body: <p>I know there are <em>many</em> tutorials on OpenGL out there, but all good tutorials I found use some C++ libraries (mostly GLM) that make it hard to follow for people that would like to use C, or/and were specific to Microsoft Windows.</p>
  
  <p>My Questions are:</p>
  
  <ol>
  <li>Does anybody know a good OpenGL 3.x tutorial that uses C and is not Windows specific? </li>
  <li>Which programming language does the OpenGL "redbook" use?</li>
  </ol>