Piddle back ends

[Pop Tufty]

Folks,

Piddle 1.0b8.2
python 1.5.2
Slackware 7.1

The piddle distribution includes basics.py, a simple
python app that draws various graphics to a canvas
and then writes the canvas.  It mentions that you can
modify this to use various backends so you can output
the image in various image formats.

It comes with the PDF output  format, which works fine,
but when I tried to exchange the format to GL, PS, PIL,
QD, or TK, it gave me errors when it ran.  Interestingly
enough, some of these errors were now shown until I
changed the name of the output file!!

The problem with PDF is that acroread gets fired off
to read it, and xv can't convert it to a GIF file.  Has anyone
had any luck with backends other than PDF?  What should
I use to generate a GIF image?

thanks - pop