Fiole format used by Renato's point viewer(s):

"pnt
format ascii 1.0
comment PLY type vertices plus splat attributes
element vertex 137062
property float x
property float y
property float z
property uchar red
property uchar green
property uchar blue
property float nx
property float ny
property float nz
property float ex
property float ey
property float ez
property float size
property float ell
property float ratio
end_header
-0.005537 0.004364 -0.049472 254 151 151 0.005755 -0.003451 -0.999978 0.995284 -0.096814 0.006063 0.000520 0.000604 0.669071
-0.005269 0.005518 -0.049460 255 189 189 0.025511 -0.007018 -0.999650 0.990301 -0.136437 0.026230 0.000511 0.000601 0.678726
-0.005202 0.005800 -0.049460 254 198 198 0.033275 0.019435 -0.999257 0.990371 -0.135072 0.030352 0.000501 0.000584 0.686452
-0.005293 0.003722 -0.049458 254 153 153 0.017671 -0.001915 -0.999842 0.993223 -0.114856 0.017774 0.000515 0.000601 0.669507
...
"

Explanation of fields:

x,y,z        vertex coordinates
red,green,blue    point color [0,255] unsigned char
nx,ny,nz    vertex normal
ex,ey,ez    major ellipse axis direction (ignored in this viewer)
size        radius of disk
ell        major ellipse axis length (ignored in this viewer)
ratio        ellipse axis aspect ratio (ignored in this viewer)

Thus you can easily generate points with circular disks and display them with this code.
(Note it uses vertex and fragment programming and textured point sprites!)