Fractal flames are much more computationally intensive than other fractal screensavers - so much so that even a top-of-the-line computer right now still takes minutes to generate a single frame. Each file you download from the server is the contributed work of up to 120 other people's computers processing frames and uploading them to the server. You can grab sheep packs from here: http://sheepserver.dreamhosters.com/megapacks/ and run entirely offline if you wish, but you'll never see the newest sheep that are born.