All modern 3D video cards support some form of hardware-based "anti-aliasing" for games. The idea is to render the frame bigger than the screen resolution, and then downsample it to get smoother images.
NVIDIA has a small description here.
Now, this might be expensive to do in a game (where the video card has a lot of processing to do), but on a desktop environment (think of Windows or any Linux graphical frontend (KDE, Gnome, LMDE, XFCE, etc.) performance shouldn't be a problem.
Therefore, one could then disable all software-based aliasing, and let the video card do the job. I guess that in several cases it would look better.
While this seems technically feasible, I couldn't find anywhere how to do this.
So, any ideas if this is possible? If not, why not?