title: DirectX HAL specification
body: <p>Where can one find the DirectX HAL specification?</p>
  
  <p>Taking <a href="http://files.myopera.com/NoteMe/albums/351845/ddi-hal-gdi-relationship.png" rel="nofollow noreferrer">this diagram</a> to be correct</p>
  
  <p><a href="https://i.stack.imgur.com/B0WMB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/B0WMB.png" alt="alt text"></a></p>
  
  <p>Then all GPU vendors have to write their device drivers such that they speak to the HAL.</p>
  
  <p>Where is the HAL specified?  How does MSFT adjust or update the HAL?  When does the HAL change?  If the HAL changes does the world break or the sky fall?</p>