Animated images as layered gifs

If you want to show the same animation several times you should possibly go for layered gifs. GIF-Images may contain several pictures (layers) which are shown subsequently at a defined speed.

A problem with this approach, however, is that due to the unclear patent situation for GIF's compression algorithm it may be difficult to generate layered GIFs online. Generating multipart PNGs, as described in the next section, is more flexible, since you may generate a new animation for each participant on the fly.