title: How is OpenGl Implemented in an Operating System?
body: <p>I'm looking into linux and Graphical API's, however I'm confused at how opengl is implemented in operating systems. 
  Is it just a set of libraries that use the kernel to "talk" to your graphics card about which pixels to colour or not? 
  if so then I don't know where the pipeline comes in - how 3D scenes are rasterized and shaders effect geometry.</p>
  
  <p>And How Come GPU's can support shader languages from both DX and OGL? - and where do shader languages actually fit?- are they compiled, or interpreted at runtime?</p>
  
  <p>I don't have very much experience with graphical API's myself despite using several game engines - usually the nitty gritty is far lost with several layers of abstraction.</p>