I was looking for a contour script and I found one but I've encountered a problem. The problem is that the file has two different extensions. The script can be found here: http://registry.gimp.org/node/27801

Is there a way to make the script accessible?

try renaming it to .py and put it in your GIMP's /plug-ins/ folder.

I will try that and see how it goes. Fingers crossed!

I got it to work. I have attached the file.

Once gimp is restarted, the file can be found here:
Filters>HaryArt>Contour

Credit goes to HaryArt for the plug-in.

When I use it, I end up with a blank transparent image and no result. How strange.

Edit: When I remove the alpha channel from the image, the script works.

That's the result I got too, Mahvin. I guess the script doesn't like it when alpha channel is in use.

If Ofnuts comes here, very likely he is able to understand the code and find the reason why and thus fix it.