I'm almost positive it uses DX.
And now I looked it up, and am 100% positive.
Yep, DX 8.1 to be precise, and no OpenGL at all, unfortunately.
Also, there's a new beast around, this Ogre wrapper...struggling to get OpenGL to work
http://gmc.yoyogames.com/index.php?showtopic=455439&st=0And it's using the LGPL licence!!!