For very large frames or images, such as desktop backgrounds, there are limits
with CLISP on 32bit machines. In such cases the image data can optionally not
be allocated and rather it will be written to a file or standard output directly.

To generate a desktop background, edit the ./quad-desktop.sh file to specify
your desktop resolution and then run that script to create an image0.pnm file.
Convert it as needed to actually use it. For example:

	convert image0.pnm desktop-background.png
	display -window root ./desktop-background.png

Run the ./create-video.sh file to start rendering a complete movie. Most of the
work is described in the ./mandelpnm.sh file, which by default uses the
+keyframes+ variable from mandelpnm.lisp as a set of zoomed in frames. You can
explore a bit in Fractint and then define a similar variable for use
in the script file instead.