For StdDIS, if it is shared by all greencard-generated source, then it probably should be something like Greencard.StdDIS and kept in a separate greencard package.
Only minor problem with making it a separate package is that the primary purpose of StdDIS is to provide the DISs which tell GreenCard how to marshall ints, floats, ptrs, etc. - the Haskell code it contains is a fairly minor part. So, if it is to be usable from other packages, the other packages need to be able to read the raw source code of StdDIS not just access a .hi and .o file. I'm not sure how will this fits with the package story.
For now, putting it in Graphics.X11.StdDIS (and not advertising its existence) should be fine.
I'll do that.
HGL is assigned Graphics.HGL, which seems like the right thing.
Ok, I'll put it there.
Or Graphics.Rendering.HGL as Malcolm suggested (actually this is probably more accurate).
To me, the word 'Rendering' suggests that it can (only) do output (drawing graphics) but HGL also does input (reading keyboard and mouse events). So I think Graphics.HGL is more accurate. But the same argument surely applies to OpenGL too (???) so maybe I'm reading too much into 'Rendering'? -- Alastair