Make antialiasing optional with some kind of flag.

More sofisticated antialiasing.

Make it possible to render into a pixmap in core.

[New and better shading model (CG&A Nov 90)]

[Shaped lightsources, e.g. point, spotlight]

[Colored lightsources]

[Several rendering modes, e.g. wire frame, hidden line, flat shading, 
 Gouraud shading]

[Arbitrary number of "texture coordinates" (numbers to be
interpolated over polygon surfaces).]

[Have the program whistle while it works with a verbose flag.]

[Shadows, see eg article in siggraph 87 about depth maps]

[Curved surface rendering (not siPp any longer)]

