pngs are indeed better gifs, they are in 24 bit plus alpha chanell and they are better packed, e.i. smaller size. far better than tifs, and not "lossy" as jpgs. since lot of "modern" graphic programms can read & write pngs, and none of them writes rsrs, this desicion from cl can only be greeted. it allows better thumbnails in the side bar, as you can render directly as xyz.png... anyway, as far as i know... can they be animated also?