title: What's "in" and "out" of OpenGL-ES? (Porting from OpenGL)
body: <p>It seems that all of the documentation I can find about OpenGL-ES says something to the effect of "OpenGL-ES is just like OpenGL, but without a lot of stuff.  For example, there's no glBegin or glEnd."</p>
  
  <p>Ok, that's great.  So, what ELSE isn't there any of?  Or is there a list of what's <em>in</em>?  Or maybe a porting guide?</p>
  
  <p>(Specifically, I'm trying to move an existing GL app to the iPhone, although I don't want to necessarily limit my Q to the iPhone.)</p>