The animation can be saved as animated GIF afterwards. It is intended to be used on websites. Have a look at the demos below. I suggest to use the defaults on the first run. Try an image size of 500x100 pixel.
All parameters are in pixel.
Using special layer build-up, you can produce very nice effects like in the example below. The Windows code without doubt has bugs, though. Here is the xcf-file . Christopher Curtis who provided patches for G1.1 on some early scripts.