   Custom MSAA resolve?
  Which extension or other method do I use to access the subsamples of textures and depth buffer in OpenGL the way it can be done in DX10.1?  I need this not only for HDR rendering, but also is needed to implement the stencil routed k-buffer (NVIDIA D3D SDK 10.5) which is the fastest way to render layered transparencies properly; depth peeling is too slow.   
NV_explicit_multisample. NVidia-only at this time.;  Great!   